🎁 Free diagrams: cleversolarpower.com 📖 My best-selling book: cleversolarpower.com/off-grid-solar-power-simplified 💵Use coupon code: clever6 to get 6% discount for Litime batteries: cleversolarpower.com/litime (cheaper than amazon)
Your book was the 1st one I bought on the subject of Solar Power. I bought others, but kept referring back to yours for a simple clarification. The content and ease to follow on the various subjects is excellent. Many Thanks 🙏🏼
This is incredible! I can tell you, that I have visited all solar specialists along the Queensland coast, from the NSW border to Rockhampton, where they have no idea how to calculate the capacity of a 12 volt battery to produce 240 V. Using their own words, they had no idea how to calculate it and some said you just need to purchase additional 12V batteries to calculate it. Of course it has taken me until now to learn how to calculate it. Cheers
Per your comments @ 1:21 & @ 1:49, it would seem a Lead Acid Battery Pack should also be given that "25% Buffer", meaning a 400 Ah x 48V pack, or 4S4P Pack is really safer! But, most Lead Acid Batteries aren't rated at "0.2C" they are rated at a "20 Hour Discharge Rate". A 0.2C is actually a 5 Hour Discharge Rate (5 x 0.2 = 1.0). So a 20 Hour Rate, is 0.05C (20 x 0.05 = 1.00) You can find "Some" Lead Acid Batteries, rated on a 10 Hour Discharge Rate, as well, if you get the Higher Priced And more Exotic ones. However, this still doesn't count that Lead Acid Batteries shouldn't be discharged to "Dead" or "100%", but in normal use, should never be drawn down below "50%" of Rated Capacity! (If you want any meaningful Lifespan from them!) 😲
max life a bank never should go below 25%, but between cost and size the standard for most is 50% depth of discharge, so basically once you calculate needed run time, add a safety factor, you either multiply it by 2 (Cost/life span ratio most go with) or by 3 best life but higher cost. But he was correct in absolute bare minimum to operate an inverter with out destroying the batteries (And possibly inverter) is a 100AH battery, but be pretty useless functionally due to next to no run time.
I ran my house off grid with 2 kilowatts of panels. 80 amp charge controller, 500 amp hour batteries(6 12 volt caravan batteries), 3500 watt sine wave off grid inverter. I never ran a heavy load at night. 24 volt system. This is in the UK. Worked great for at least 9 months of the year. I fitted a separate rings mains so I could switch to grid with a different socket in each room.
Yea, I agree it's best to size the inverter to a margin above the expected peak load. The total battery capacity would be determined by the expected average load, as would a solar array(plus a region/sunlight-based margin) and battery chargers. Oversized inverters for a modest average expected power consumption has little effect, other than the idle current used to run the circuitry.
i.e. - More unnecessary and undesired idle current draw from an oversized inverter in porportion to the battery bank (thus draining the batteries faster while inverter/ batteries are not in use). The problem though in this equation, is cheap inverters which cannot deliver the current (amps/ watts) which are stated on the inverter. So I always oversize even with expensive inverters and then oversize battery and solar array commensurately (when and where possible/ practical). The batteries will always outlast the inverter if used properly.
"Limit current to 100 Amps..." This is why I shall do a 36V system. And your explanation of the C-Rates of batteries explains why those Telephone Central Office Backup Banks I installed were so huge. I'm a retired electrician, and, frankly, managed to miss that day in class.
Maybe you can help. I use electrodacus system, but it's 24v. Is there a better system on the market? I still don't understand the rationale for using 100A system. My batteries are prismatic cells and they come in 280Ah configuration.
@@gushardy4421 We're referring to the LiFePO4 Batteries, and the Battery Management System (BMS) they have inside them. The Battery may very well have a rating of 280 Amp Hours (AH), but a Battery management System that only allows a charge or discharge rate of 100 Amps. In a 12 Volt system, this limits you to a 1,000 Watt load. If you use a 24 Volt system, you can double that to 2.000 Watts. P = I * E. Power (In Watts) equals Volts times Amps. We doubled the voltage, we doubled the watts available. And don't need to get bigger wires for the moar Amps. You mileage may very, and your 280 AH Battery may well have a 280 Amp BMS. And it may not. So, with 2 Batteries as a 24 Volt system. IF they have 100 Watt BMS's, you're capped at about 2,000 Watts of load. If, however, they have 280 Amp ones, 280A X 24 V = 6,720. For safety reasons, always set things up so you only pull 80% of the possible Maximum. So, 5,000 Watt, rounding down to a nice even number.
@@gushardy4421Ah, amp hours and Amps are not the same. When your prismatic cells are set up in 24v configuration, you will have 280ah capacity, but you still need your BMS, battery management system, it's a circuit to control amps out, and amps in,charging. Without a bms you will kill yourself and anyone around you. So you can buy 100 amp, 200 amp bms, now 3000w inverter ÷ 24v = 125 amps, so 1 24v280ah battery pack w 100amp bms is not enough, you need 2 24v280ah 100amp bms battery packs so the 2 packs split the amp load which is 62.5 amps pulled from each pack, so your inverter has enough power to run full speed. Or 1. 24v280ah 200 amp bms battery pack. I hope that turned the light on for ya
Hey Nick you are the main man and best person to answer this for me. This is a van life situation using the Ecoflow delta pro. The alternator chargers they offer cost 599$ each so what I want to do is purchase a large car audio high output alternator use a 3000 watt inverter so that I can charge the delta pro with ac voltage at about a 20 amp draw. This will offer me a faster charging alternative to the limited amount of solar I can install on a van. All with proper Guage wiring and fuses of course. And with the delta pro I can control the charge rate. Can this work if done correctly? You can just say yes or no or drop me one of your video links to point me in the right direction. Thank you for everything man
Love reading all the comments. So much talk and so many ideas. Simply put, i have a 5kw inverter with 6.6kw solar panels and a 9.6kw battery. The inverter is hybrid so it charges my battery bank and i use my battery to then run my inverter which gives me my household power. 5kw is enough to run everything in the house except for my 7.5kw ducted air con. I did not bother to increase my inverter to cover the aircon as it will rarely get used and when i do use it then i can tap into the grid power. But the 5kw inverter is 96% efficient so i can run it at around 4.5kw comfortably, which is enough as mentioned to run the house, day and night.
I installed a 3KW pure sine wave inverter together with six 110 AH 12 volt leisure batteries wired in parallel on our boat six years ago. I didn't do any calculations. It was just my gut feeling of what was needed. We have a 230V fridge, a 230V 26" LCD TV, a 230V microwave, a 2KW 230V Electric kettle, a 17 inch Laptop PC run with a 230V charger and can go away from the mooring for a week at a time and run those things with no issue. We do have a diesel powered, 12 KVA generator installed too but rarely use it.
@@afzaalkhan.m My inverter requires a 12v supply. Running six 12v batteries in series would produce an output of 72V. If you look at the diagram at 5.29 in the video above, you can see three lines of batteries. The horizontal lines are in series giving 48v and then the three lines are connected in parallel vertically to give 300 Ah.
that would be 72v @110AH per 20hrsseries instead of 12v @ 660AH per 20 hrs. parallel. He could have also tried 36v@220AH per 20hr load with three sets of 12v batteries in series / parallel.@@afzaalkhan.m
I have a 20w solar panel, 30a charge controller,12v 7ah battery and a 200w inverter. Is using the 7ah battery with the 200w inverter to charge my 33watt phone ideal
This is why some people like all in one power supplies. They don't have to figure this stuff out. I know this system is cheaper and more flexible but some people would rather pay the extra cost and go with a plug and play set up. Your presentation was excellent!
It is true that all in one systems require less wiring. But if one components breaks, the entire system goes down with it. So as a reliability standpoint, not so great. You still have to figure out battery sizing though. You should not connect a single 12V 100Ah battery to a 3kW all in one system. Because the sizing is totally off. People also do not realize that all in one system consume power when on standby. A 3kW unit with MPPT, inverter and charger can consume 30W idle. Thats 720Wh, a little more than half the capacity of a 12V 100Ah battery for just sitting there being turned on.
You actually sound like you know your subject ! Congratulations ! I have my doubts about many presenters on this platform as they often do not sound confident . Have a great year & life ! I will be buying your book , I bought Will Prowse book but when Amazon did not fulfill after payment was made, Will ignored me.......
Thank you, that means a lot. Have a great year too. People who buy my book can ask questions through email, so if you have any questions, feel free to ask.
I've seen some massive failures in the corporate world because people who sounded confident actually didn't know what they were talking about. Confidence and competence are different things.
Great info for longer-term setups. For short term, I use a 12v 100AH battery connected to a 3000 watt inverter. My total amp draw is about 12 amps per hour if I opt to run everything I need at the same time. This carry's the load for about 6 hours. I have a second battery that I charge on a propane generator while the other one is carrying the load, then switch them out. It takes about 1.5 hours to charge the battery, and I get about 14 hours of run-time on the generator for a 20# tank, which means I could get about 48 hours of power to the things I need. (TV/Internet/fridge/freezer/window AC unit/ portable heater/etc as each is needed) - I normally do not run everything 100% of the time, for example the window AC unit draws about 800 watts/5 amps by itself, so I tend to only run that intermittently, and hunker down in just one room with it running about 20 minutes per hour on average. - Same for a space heater if it is cold, though it has an even higher current draw)
Don't forget that a 3kw inverter will consume about 30-50w just idling. That's 720wh-1200wh daily. You can use a small but efficient victron inverter for small loads and turn off your 3kw inverter when you don't need it.
@@LotsaThingsNstuff - There is normally a label on the items that posts the amp draw (or at least the watts, and you can then calculate the amps - but always account for the initial surge, which is normally higher (briefly) than the stated running watts or amp draw)
Everything is based on usage. Your not going to run everything at the same time at least I hope your not going to . I use 12v backup lighting and run a 2000w inverter for fig and freezer. I use 6 lead deep cycle batteries 780ah each backed up with 800ah solar and one 200ah wind turbine. I can go for months without needing to charge with normal means . This is a backup only system not living off of it
As a system builder I'll verify what he said is accurate, and must say one of very few I have seen to do it accurately. As to charge controllers another way to look at it, with a quality charge controller, at 12v best you can do is 750w, but at 48 same unit will do 3.5kw so you have more power available. a general rule, no matter the voltage the core wiring should be no less than 2 awg imo
No, it will not harm your batteries or inverter. You just need bigger cables to handle the high current. Your charge controller will be more expensive, but other than that no harm done.
A really well structured video, Thank you for being ome of the very few people who introduce your topic by outlining what you intend to demonstrate. ✴✴✴✴✴✴✴✴✴✴
New to your channel, I'm trying to apply your formulas to my case but I'm having trouble using the C rate of my AGM Renogy 200A/H battery, it seems that it's 0 05C, is that correct? My setup is basic 400W solar with a 30A PWM charge controller and a 2000W inverter. The main use is to keep the fridge/freezer (300-400W) powered by the inverter while we tow the trailer, therefore without using the propane power. Do you see any issue with this installation? All comments and responses are welcome Cheers Phil
so I have 3x 105 AH battery bank. for 315 AH - planning a 2000 watt renogy invertor with 1/0 cable and a 250 AMP fuse. SOund good? we will almost never use appliances over 1k watts. we wanted the extra just in case. does this sound OK? 12v AGMS
Small battery bank will have very short run times, AGM's are easy to kill very sensitive to charge voltages. The fuse is sized to protect the wire, not your devices, but with single aut you're fine with that fuse.
The 12V 100Ah Renogy AGM Battery you pictured far out paces your C-rate calc of 20A. It is rated at 30A with a 5 second rating of 100A! A couple of these tied to a 2000W inverter works wonderful in a typical RV.
It could deliver 1100A, but do that a few times and you will have a dead battery. Deep cycle gels or AGMs are not made for high current. Can they do it? Yes. Is it ideal? No.
No battery is good at high current. Geez, if makers would just get off of playing with the numbers trying to fool us to sell a battery. If you want high current, use super capacitors,@@cleversolarpower
where does the 0.2c discharge rate come from? I have never seen that specified by a manufacturer. I have seen a 0.1c charge rate for lead-acid batteries, which makes charging them decidedly slower.
It's specified in the datasheet of batteries. The capacity is mentioned in ah at a 20 hour rate. This is 0.2C. The manufacturer would list the capacitiy of their batteries at a 20 hour discharge rate. It's also known as C20. Check my video about C-rate.
@@cleversolarpower Yes, of course - the marketing term. They advertise 100AH at the 20 hour rate - *0.05C, actually.* That is only a measly 5 Amperes (continuous). However, it is not necessary to be this conservative. Otherwise, no one would be able to start their car in the morning. What needs to be looked at is a series of curves. And decisions made on the trade off between capacity performance and the number of charge cycles over an acceptable lifetime. If you discharge continuously at 100 Amps, you might get something like 70AH out of it, in much less than an hour. (Mfg. vary) but you wouldn't want to market it this way. And sure, you will get longer run time and longer life if you take it easy on the current demand. But most real-life loads (except heating) have an intermittent duty cycle. So lets look at my conservative design. 3 pieces of 12v 105AH AGM batteries in parallel. I want to use 50% of that capacity, or 157 AH; or 1,800 Watt-hours (nominally). And I like the idea of limiting to 0.5C for discharge and 0.1C for charging. And that gives me slightly over 150 Amps. Well, the inverter I chose is 2000 Watts, which is 167 amps at full capacity. I like to de-rate the load to 80% which would draw about 133 Amps. I have no problem doing that 0.42C continuously down to 50% State of Charge (SoC), which should last for about an hour. Then of course making the battery happy by getting it fully charged again. I use a 30 Amp smart charger for this rig. Also, with lead-acid chemistry, I have the headroom to support the full rated 4,000 watt motor starting capacity (inrush) current of 333 Amperes. Thanks for the videos! Cheers!
You are oversimplifying a bit. Its not how big your inverter is but more what load you will put on it. Also you should have larger inverter than you need for starting motors unless you buy a coil based inverter. I'm running a 24v 960ah LiFePO4 system using a 3000 watt inverter. My daytime load (highest) is about 1000W. After a couple of days of cloudy skies, my batteries are empty. I could really use a larger battery however I don't have the solar capacity to support it (3.7kw) especially during the winter months.
Thanks for your feedback. You have to size for the inverter, not for the load you attach to it. Startup surge power is a whole other topic that I can make another video about. It's impossible to mention everything in a short video.
@@cleversolarpower - No, you do NOT have to size for the inverter. You have to know your loads and size the inverter to easily handle those, without pushing it too hard. Then you have to size your battery storage and your solar array. You keep acting like you have to go 100% all the time on all of these components, and that is most certainly not how any of this works, or should work.
@@2hotscottpro May I ask what you are looking for to buy. My batteries degenerated very fast (see my comments here) and I'm looking for a replacement. As far as i can see the best option is lifepo04. I’m looking at the brand Li Time.
Have not installed yet I purchased a 3000 W inverter that will handle a 6000 W. I don’t recall the amount of time but it’s a start of it for starting large motors and things load.
Something you could talk about is using busbars like in your diagram. I bought some aluminum 1/8 x 3/4 stock and cut it down to 6" with two holes drilled in it for battery connections on my lead acid setup. Seemed to work good. I want to go with copper for my lithium hookup but no one talks about it and it seems everyone expects us to make interconnect cables. They also talk about using the same size for all cables and it seems to me interconnect battery cables for a 48 volt doesn't need to be as large as the wires going to the inverter. Large cables to the busbars where all the 48 volt batteries connect to. Very good video, thanks and I liked it.
At 5:25 the setup shows 12 batteries? But doesn't the calculation formula you show say 3 batteries. 12volts x 4 = 48volts, and 100ah x .2 x 4 = 80amps...? Or is it when the batteries are wired to make the 48 volts the 4 together count as one and can still only output 20 amps?
Good question. Each battery should output a maximum of 20A. Less is better of course. So with 4 12V batteries in series each battery delivers 5.2A. We need 48V, to stay under (my recommended) 100A to keep the system correctly sized. You don't have to stay under 100A, it's just my recommendation for DIY off grid systems. I made a video similar to this one showing how many 12V batteries you need to have to run a 3,000W inverter.
Thanks so much, I ordered the free diagrams. But one feedback: for some reason this video is blocked for saving to my solar power playlist for future replays and reference. Why have you blocked this option? Usually that option is only blocked for videos not suitable for children.
Im a bit confused i have a 2500watt mig welder max 90amp. Thinking about fitting a 3000watt inverter in my garage what battery would i need to run the above thanks.
What's the absolute top surge amperage when you create your spark, that could b well above 3k. Then you need to decide whether you want 48/24/12V batteries. Then you need to decide what chemistry you will use, lifepo4, lead acid, gel etc. Then you need to figure out your usage over time in order to size your array. There are many steps to take on your journey.
I use 12v lighting in every room and 2000w inverter for frig and freezer. Supply power is 800w=8 amps solar 200w=2amps wind feading 6 lead deep cycle 780ah batteries. Now given we dont run all the lights and kids dont leave frig door open lol i can run for months without needing charged from normal means . I set my system up for backup only (just incase) but i know im good to go . Off grid if need be
Absolutely brilliant information. I have got my own solar systems running, one being a 12v and another a 24v. However, I am trying to check how much can they handle, so that I can assign specific gadgets to each one of them - right now in the middle of testing. The fridge, kettle work and the slug wire trap system work OK, more things to add. Your calculations are excellent, this will definitely help know what to add where, as I plan to upgrade both system a bit.
I have a 3000W inverter, to run it at full capacity I need 4 lithium batteries because I need 2 to make 24v and 2 alone can only give 100A at 24v which is 2400w, so I need 4 of them to be sure to have enough to run my 3000w inverter at full capasity. (it can also use 6000w for a short while but the batteries can also provide more Ampere for a short while so it balances out).
I like how I can go back over the information and get a little better understanding, I think calculating sun hours and number of panels will tell me what I can afford i.e what size will my offgrid setup cost which in turn will tell me what I can run, cheers mate
That would make it a 24V 200Ah battery. 3000W/24V=125A*1.25=156A It is possible, but I recommend using a 48V battery because of the mentioned benefits of having a higher battery voltage.
@@cleversolarpower - You don't have to connect them in series. You can have 2 x 12v 200ah batteries. Each will only deliver half of the needed amperage. That's still a lot of draw for a 3,000w inverter, but if you're using an inverter that large, you should have a larger battery bank, anyway.
@@jasonbroom7147 Indeed. But connecting in series will increase the diameter of the wire. Overall just having two batteries is not enough for a 3000W inverter like you said.
@@cleversolarpower - Since when has connecting batteries in series meant you need to increase the diameter of the wire? It is very common knowledge throughout the solar industry that you go up in voltage (which a series connection does) so you can use SMALLER wires, not bigger ones. I'm starting to get the sense that you are really new to this and don't actually know what the Helsinki you're talking about!
Something's off about the math on the diagram featured at 5:24 time stamp. It says to get 48v/300 amps to wire it in the sequence shown. But each battery is 12v/100Ah so wouldn't it be 48v/1200Ah? 12v/100Ah x 4 would equal 48v/400Ah, and then multiply by 3 sets wired in series.
@@cleversolarpower I'm not referring to the wires, I'm referring to the total amp hours at the top of the diagram. It shows 4 batteries in series which by math 12v/100Ah would be 48v/400Ah. Plus there's 3 rows of that, which multiplied by 3 would be 48v/1200Ah.
Thank you for the clear video, I agree with its content but feel it slightly ignores a key dimension to this issue: it is mostly centred around the idea of running an inverter from a single battery only. In that case obviously higher voltages will fare better than lower voltages because they will require less current. But isn't it the case that you can supply the necessary input to the inverter within the relevant "C" constraints of your battery chemistry by adding more batteries in parallel. I am happily running a 3000W inverter using a set of six 24V (110AH) LiFePO4 batteries in my off grid cabin - at 3000W the total current is 125A but each battery is only discharging at a sixth of this because they share (equally, according to the bluetooth instrumentation they display) in the supply of that current. Did I miss something?
G'day man love your show. I have a question if you don't mind. I'm getting a portable block Redarc install in my vehicle it does not have an inverter so watt power inverter should I get I would appreciate your help Dave
I dont know what a redarc is, but i assume it's a battery with some usb chargers,... It depends on the BMS inside, some have a 100A BMS, some less. It should be in the datasheet of the product you got (the redarc).
I loved the video. Maybe someone has already said something, but I think I see an error. At 4 minutes & 42 seconds in the video on the "Lead Acid Battery Example" it shows 3 lead acid batteries instead of 4. Making it 36 volts, changing the breaker to a 83.33 AMPs. Maybe you meant 4 Batteries. Otherwise, I am thinking this would mess up the calculations and burn out something? I would like to know for sure. Thank you.
It's a minimum of 3 batteries. That would indeed make a 36V battery system, but our inverter works on 48V. So we have to increase it to 48V and then we have 4 batteries in series.
Before. So you can safely work on the system without power feeding into it. Technically, you can have disconnects between all components, to ensure you can work on any part of the system without worry. Disconnecting power from the solar panels will not isolate or disconnect power between your battery and inverter. Most people only have a fuse between the inverter and battery, but some will use a breaker, so they can switch off the power from the battery to the inverter.
The 80A fuse you recommended, is that the AC fuse for the Inverrer? If yes, don’t you think that would be too much, especially, with a lead acid battery setup, considering that you would only be pulling and also charging at a current just around 20% of the battery capacity rating, per hour?
I have 700 watts of solar, two 206 AH lithium ion batteries and a 3000W inverter in my camper. It works great. I can run the AC for short periods of time but i prefer to use a generator for that. I'd like a bit more solar and a third battery so I'm covered for winter, but that's a ways away. I'm out of room on my roof so that's one problem.
I have 6 100W panels, 2000W inverter, Lithium Ion 300AH 12.8V, and 120A Charge controller, ....by. your calculation, 2000/12.8 = 156 A .... will the Amp load be too high? do I need to buy another 300 AH battery and wire it in a series in order to lower the amp load? if I hook it up as is will it explode
Thank you for the video. How about a practical example in the end? Like with the 48v 100amp hour, how many hours can I run a 15 amp window ac unit and how long to recharge with a generator like off grid or during a power failure scenario. I appreciate the math, but I need to know run times and re-charge for better context.
I have a question about inverters and batteries. I’m renovating my caravan with 240v wires throughout. I only plan to run a fridge, convection oven, lights and a tv and dvd player. The fridge will be the only one running non stop (while travelling around). The fridge is 240v 50Hz 0.73A 106W. How do I work out what size inverter and battery do I need?
I advice against a convection over. It draws a lot of power. For the fridge, multiply the power consumption by 8 hours, which is a 30% duty cycle. 106W*8h=850Wh I made a video about system design, look it up on my channel page.
We have an alternator of 12v in a van vehicule, how can we install a system working at 24V or even 48V in order to be below 100A when requering high power, such as 3000 W and higher. I do not have clear how to charge the batteries using the van alternator. Many thanks
If you want to charge with your alternator I recommend 24v systems. I haven't found any DC to DC charger that is 12-48V. I have a video about different voltage systems in a few days. You would have to sacrifice some efficiency using higher than 100A, it will be more expensive, but in an RV this is what I recommend. Recently I installed a 24v 280ah battery in an RV.
@@cleversolarpower Many thanks for your prompt answer, I fully agree. Can you recommend any buck boost to increase de voltage from 12v to 24v in a RV? I am facing some problems to find one with enough power at a reasonable price.
to me there is no reason to run a 24v or 48v on a rv at all stay 12v and just get a big battery bank at 12v then you can get a 200-370 amp high output alternator if needed and can get a few solar panels on your roof in most cases on a RV you have all short cable runs and very small space for solar panels so there is not need to to go with a higher voltage system at all and they make lots of 3000 watt 12V inverters for this reason as that all you would ever need in a RV also can charge very fast with the engine running and run everything at full load no problem
take the C-rate of the battery and multiply by the capacity. if each battery has 0.5C discharge rate and is 12V 100Ah, then you become: 100Ah*0.5C*2 batteries= 100A max discharge. 100A*12V=1200W inverter maximum.
I'm going quick in this video, so watching it a second time might be better. To simplify: 1. increase the voltage so that the current is limited to 100A (not necessary but good for sizing) 2. increase the capacity of the battery so that the C-rate of the battery type is respected.
Sir i have solar panel that has 100watts and 12v 100ah battery with inverter of 600w-1200w But when i try to charge my laptop... battery finishes fast and inverter starts to make the annoying noise,what can i do to fix that problem?
We have 4 - 200 amp hr ion lithium batteries running 12 V with a 3000 W inverter. will be switching over to 24 V I don’t need a 3000 W inverter so is it better for me to run a 2000 W inverter with a 24 V system?
@@cleversolarpower sorry to reply only now, I purchased a luxpower 48v 5kw and AND a 5kwa battery I forget the name, I had it installed and I AM very happy it's like a power station all on its own and bcos of the inverter I changed to gas where alot of power is needed so I don't fear the power going off anymore I feel protected
Help! I have 300 watt running into a solar connector. Those then output to a 500 wat charge controller. From there I have the charge controller running into a battery. The battery is attached to a 2000 watt inverter. Am I safe or do I need to adjust anything? Heard the fan kick on.
It's safe. However, depending on the battery size, your inverter can be oversized. This is not bad, it just doesn't go together like mentioned in the video. Assuming you have sized the cables and fuses correctly. Fan kicking on is normal.
I'm trying to figure out the optimal set up for my Freightliner Cascadia transport truck that runs an electric APU with an inverter inside the bunk to power electronics. The inverter is 2000w but I'm not sure if it could handle a 5000w inverter What is the best way to contact you?
Most of the times it will work, but that does not mean it's correctly sized. As you can repeat the calculations in this video for your own use case. You can send en email to me through my website cleversolarpower.com
Totally new at this but I want to build a system to run 2 freezers for emergencies. Don't need solar to recharge since I have a gas generator to recharge with. This is all for emegency backup and I would build a separate one for a refrigerator.
You can do it easily. You have to figure out the consumption of the 2 freezers and then multiply by the amount of days you want to run them (usually 3). Then add a charger and inverter. 3000W should be enough, and I recommend using a 24V system for this.
So, to simplify, you recommend a lithium battery should be sized to have sufficient capacity (in Watt hrs) to run at the inverter's full power for 1 hour, or 5 hours for lead acid batteries.
How long do you need to run for in KwH with out that nothing can be said, and then what system voltage. I usually recommend lead acid for beginners as it is more forgiving of mistakes, then by the time that bank dies you should have saved enough to buy lithium for your more permanent bank. and the type of lead acid I recommend is Flooded traction battery (True deep cycle)
When you refer to Lead Acid batteries are you also referring to AGM Absorbed glass matt or Gel batteries also, as I understand they have quite differing characteristics to conventional 'wet cell' Lead acid batteries, ie less resistance, larger charge rates and deeper cycling 50%
sorry continuing :deeper cycling 50% than a conventional wet cell battery at 20% discharge safely for maximum lifespan. AGM or Gel batteries obviously have more capacity than conventional wet cell L/A's.
Yes, I'm referring to all lead acid battery chemistries. Which wet cell battery can you discharge to 20% without impacting it's lifespan too drastically?
🎁 Free diagrams: cleversolarpower.com
📖 My best-selling book: cleversolarpower.com/off-grid-solar-power-simplified
💵Use coupon code: clever6 to get 6% discount for Litime batteries: cleversolarpower.com/litime (cheaper than amazon)
thanks :)
😊
A professional off grid system never uses inverters such as those
😊😊😊
Thanks
Your book was the 1st one I bought on the subject of Solar Power. I bought others, but kept referring back to yours for a simple clarification.
The content and ease to follow on the various subjects is excellent. Many Thanks 🙏🏼
Thanks for getting the book and your kind words.
What is the name of the book please?
Good morning sir, thanks for your teaching but I want to learn more about solar panels installation please sir 🙏🙏🙏🙏
@@AffectionateJukebox-je4rs Off-grid solar power simplified
This is incredible! I can tell you, that I have visited all solar specialists along the Queensland coast, from the NSW border to Rockhampton, where they have no idea how to calculate the capacity of a 12 volt battery to produce 240 V. Using their own words, they had no idea how to calculate it and some said you just need to purchase additional 12V batteries to calculate it. Of course it has taken me until now to learn how to calculate it. Cheers
I worked in the battery industry for 10 years and you are teaching me new stuff in some of your videos. Well done
Thank you - What I have been trying to learn for 8 years.
Per your comments @ 1:21 & @ 1:49, it would seem a Lead Acid Battery Pack should also be given that "25% Buffer", meaning a 400 Ah x 48V pack, or 4S4P Pack is really safer!
But, most Lead Acid Batteries aren't rated at "0.2C" they are rated at a "20 Hour Discharge Rate". A 0.2C is actually a 5 Hour Discharge Rate (5 x 0.2 = 1.0). So a 20 Hour Rate, is 0.05C (20 x 0.05 = 1.00)
You can find "Some" Lead Acid Batteries, rated on a 10 Hour Discharge Rate, as well, if you get the Higher Priced And more Exotic ones.
However, this still doesn't count that Lead Acid Batteries shouldn't be discharged to "Dead" or "100%", but in normal use, should never be drawn down below "50%" of Rated Capacity! (If you want any meaningful Lifespan from them!) 😲
max life a bank never should go below 25%, but between cost and size the standard for most is 50% depth of discharge, so basically once you calculate needed run time, add a safety factor, you either multiply it by 2 (Cost/life span ratio most go with) or by 3 best life but higher cost. But he was correct in absolute bare minimum to operate an inverter with out destroying the batteries (And possibly inverter) is a 100AH battery, but be pretty useless functionally due to next to no run time.
Thanks!
Thanks Hercules 🙏
That’s the best video that I have ever understood on battery set up !
Very clearly explained with good graphics.
This is really helpful, thanks for explaining it. I am just about to DIY a solar and battery system !
I ran my house off grid with 2 kilowatts of panels. 80 amp charge controller, 500 amp hour batteries(6 12 volt caravan batteries), 3500 watt sine wave off grid inverter. I never ran a heavy load at night. 24 volt system. This is in the UK. Worked great for at least 9 months of the year. I fitted a separate rings mains so I could switch to grid with a different socket in each room.
After 9 months you had issue?
What brand inverter did you use
@@leongetz1931 POWER JACK PSW-3500. But it was faulty when I got it new from China so I`m not saying get one. But it`s worked ok since I repaired it.
@@damianbutterworth2434 thank you
Yea, I agree it's best to size the inverter to a margin above the expected peak load. The total battery capacity would be determined by the expected average load, as would a solar array(plus a region/sunlight-based margin) and battery chargers.
Oversized inverters for a modest average expected power consumption has little effect, other than the idle current used to run the circuitry.
i.e. - More unnecessary and undesired idle current draw from an oversized inverter in porportion to the battery bank (thus draining the batteries faster while inverter/ batteries are not in use). The problem though in this equation, is cheap inverters which cannot deliver the current (amps/ watts) which are stated on the inverter. So I always oversize even with expensive inverters and then oversize battery and solar array commensurately (when and where possible/ practical). The batteries will always outlast the inverter if used properly.
"Limit current to 100 Amps..."
This is why I shall do a 36V system.
And your explanation of the C-Rates of batteries explains why those Telephone Central Office Backup Banks I installed were so huge.
I'm a retired electrician, and, frankly, managed to miss that day in class.
Maybe you can help. I use electrodacus system, but it's 24v. Is there a better system on the market? I still don't understand the rationale for using 100A system.
My batteries are prismatic cells and they come in 280Ah configuration.
Limit to 100Amps is not a rule set in stone, but i like to use it to size systems for costs reasons.
@@gushardy4421 We're referring to the LiFePO4 Batteries, and the Battery Management System (BMS) they have inside them.
The Battery may very well have a rating of 280 Amp Hours (AH), but a Battery management System that only allows a charge or discharge rate of 100 Amps.
In a 12 Volt system, this limits you to a 1,000 Watt load. If you use a 24 Volt system, you can double that to 2.000 Watts.
P = I * E. Power (In Watts) equals Volts times Amps.
We doubled the voltage, we doubled the watts available. And don't need to get bigger wires for the moar Amps.
You mileage may very, and your 280 AH Battery may well have a 280 Amp BMS.
And it may not.
So, with 2 Batteries as a 24 Volt system. IF they have 100 Watt BMS's, you're capped at about 2,000 Watts of load. If, however, they have 280 Amp ones, 280A X 24 V = 6,720.
For safety reasons, always set things up so you only pull 80% of the possible Maximum. So, 5,000 Watt, rounding down to a nice even number.
@@cleversolarpower 100 Amp cable is SO much cheaper than 200 Amp!
@@gushardy4421Ah, amp hours and Amps are not the same. When your prismatic cells are set up in 24v configuration, you will have 280ah capacity, but you still need your BMS, battery management system, it's a circuit to control amps out, and amps in,charging. Without a bms you will kill yourself and anyone around you. So you can buy 100 amp, 200 amp bms, now 3000w inverter ÷ 24v = 125 amps, so 1 24v280ah battery pack w 100amp bms is not enough, you need 2 24v280ah 100amp bms battery packs so the 2 packs split the amp load which is 62.5 amps pulled from each pack, so your inverter has enough power to run full speed. Or 1. 24v280ah 200 amp bms battery pack. I hope that turned the light on for ya
Hey Nick you are the main man and best person to answer this for me. This is a van life situation using the Ecoflow delta pro. The alternator chargers they offer cost 599$ each so what I want to do is purchase a large car audio high output alternator use a 3000 watt inverter so that I can charge the delta pro with ac voltage at about a 20 amp draw. This will offer me a faster charging alternative to the limited amount of solar I can install on a van. All with proper Guage wiring and fuses of course. And with the delta pro I can control the charge rate. Can this work if done correctly? You can just say yes or no or drop me one of your video links to point me in the right direction. Thank you for everything man
Love reading all the comments. So much talk and so many ideas. Simply put, i have a 5kw inverter with 6.6kw solar panels and a 9.6kw battery. The inverter is hybrid so it charges my battery bank and i use my battery to then run my inverter which gives me my household power. 5kw is enough to run everything in the house except for my 7.5kw ducted air con. I did not bother to increase my inverter to cover the aircon as it will rarely get used and when i do use it then i can tap into the grid power. But the 5kw inverter is 96% efficient so i can run it at around 4.5kw comfortably, which is enough as mentioned to run the house, day and night.
I installed a 3KW pure sine wave inverter together with six 110 AH 12 volt leisure batteries wired in parallel on our boat six years ago. I didn't do any calculations. It was just my gut feeling of what was needed. We have a 230V fridge, a 230V 26" LCD TV, a 230V microwave, a 2KW 230V Electric kettle, a 17 inch Laptop PC run with a 230V charger and can go away from the mooring for a week at a time and run those things with no issue. We do have a diesel powered, 12 KVA generator installed too but rarely use it.
Yes, it will work.
Batteries:Why not in series?
@@afzaalkhan.m My inverter requires a 12v supply. Running six 12v batteries in series would produce an output of 72V. If you look at the diagram at 5.29 in the video above, you can see three lines of batteries. The horizontal lines are in series giving 48v and then the three lines are connected in parallel vertically to give 300 Ah.
that would be 72v @110AH per 20hrsseries instead of 12v @ 660AH per 20 hrs. parallel. He could have also tried 36v@220AH per 20hr load with three sets of 12v batteries in series / parallel.@@afzaalkhan.m
Has anyone any idea about Omron omron sysdrive 3g3fv 7.5kw inverter, please? I have one and unsure if this could be connected to solar panels system
Excellent explanation. ~Thank you
What about 12v?
You would probably need 3 batteries. Bms on a lifepo4 battery typically won't allow more than 100a and a 12v 3000w inverter would draw about 250a
get ready to spend $$$ on very big cables. the lower current of a 48v system makes wiring easier
I have a 20w solar panel, 30a charge controller,12v 7ah battery and a 200w inverter. Is using the 7ah battery with the 200w inverter to charge my 33watt phone ideal
How about for 24 volts set up..tnx
This is why some people like all in one power supplies. They don't have to figure this stuff out. I know this system is cheaper and more flexible but some people would rather pay the extra cost and go with a plug and play set up. Your presentation was excellent!
It is true that all in one systems require less wiring. But if one components breaks, the entire system goes down with it. So as a reliability standpoint, not so great. You still have to figure out battery sizing though. You should not connect a single 12V 100Ah battery to a 3kW all in one system. Because the sizing is totally off. People also do not realize that all in one system consume power when on standby. A 3kW unit with MPPT, inverter and charger can consume 30W idle. Thats 720Wh, a little more than half the capacity of a 12V 100Ah battery for just sitting there being turned on.
You actually sound like you know your subject ! Congratulations ! I have my doubts about many presenters on this platform as they often do not sound confident . Have a great year & life ! I will be buying your book , I bought Will Prowse book but when Amazon did not fulfill after payment was made, Will ignored me.......
Thank you, that means a lot. Have a great year too. People who buy my book can ask questions through email, so if you have any questions, feel free to ask.
I've seen some massive failures in the corporate world because people who sounded confident actually didn't know what they were talking about. Confidence and competence are different things.
Great info for longer-term setups.
For short term, I use a 12v 100AH battery connected to a 3000 watt inverter. My total amp draw is about 12 amps per hour if I opt to run everything I need at the same time. This carry's the load for about 6 hours. I have a second battery that I charge on a propane generator while the other one is carrying the load, then switch them out. It takes about 1.5 hours to charge the battery, and I get about 14 hours of run-time on the generator for a 20# tank, which means I could get about 48 hours of power to the things I need. (TV/Internet/fridge/freezer/window AC unit/ portable heater/etc as each is needed) - I normally do not run everything 100% of the time, for example the window AC unit draws about 800 watts/5 amps by itself, so I tend to only run that intermittently, and hunker down in just one room with it running about 20 minutes per hour on average. - Same for a space heater if it is cold, though it has an even higher current draw)
Don't forget that a 3kw inverter will consume about 30-50w just idling. That's 720wh-1200wh daily. You can use a small but efficient victron inverter for small loads and turn off your 3kw inverter when you don't need it.
How do I find how many amps I'm using? My system doesn't seem to have that capability...
@@LotsaThingsNstuff - There is normally a label on the items that posts the amp draw (or at least the watts, and you can then calculate the amps - but always account for the initial surge, which is normally higher (briefly) than the stated running watts or amp draw)
@@LotsaThingsNstuff A=W/V or Amps=Watts/Volts Ex: in a 12v system 1500 Watts / 12 Volts = 125amps
Everything is based on usage. Your not going to run everything at the same time at least I hope your not going to . I use 12v backup lighting and run a 2000w inverter for fig and freezer. I use 6 lead deep cycle batteries 780ah each backed up with 800ah solar and one 200ah wind turbine. I can go for months without needing to charge with normal means . This is a backup only system not living off of it
Very useful. I send it to my clients when dealing with what's needed in there RVs.
As a system builder I'll verify what he said is accurate, and must say one of very few I have seen to do it accurately. As to charge controllers another way to look at it, with a quality charge controller, at 12v best you can do is 750w, but at 48 same unit will do 3.5kw so you have more power available. a general rule, no matter the voltage the core wiring should be no less than 2 awg imo
I have 3 - 12v 300ah lifep4 batteries and a 12 v - 3000 w inverter.. will it harm my batteries since I can not reach 48v
No, it will not harm your batteries or inverter. You just need bigger cables to handle the high current. Your charge controller will be more expensive, but other than that no harm done.
@@cleversolarpower hey, thank you for the response. I wasn't expecting to receive an answer honestly, much less so quickly. Will subscribe.
A really well structured video, Thank you for being ome of the very few people who introduce your topic by outlining what you intend to demonstrate. ✴✴✴✴✴✴✴✴✴✴
New to your channel, I'm trying to apply your formulas to my case but I'm having trouble using the C rate of my AGM Renogy 200A/H battery, it seems that it's 0 05C, is that correct?
My setup is basic 400W solar with a 30A PWM charge controller and a 2000W inverter.
The main use is to keep the fridge/freezer (300-400W) powered by the inverter while we tow the trailer, therefore without using the propane power.
Do you see any issue with this installation?
All comments and responses are welcome
Cheers
Phil
so I have 3x 105 AH battery bank. for 315 AH - planning a 2000 watt renogy invertor with 1/0 cable and a 250 AMP fuse. SOund good? we will almost never use appliances over 1k watts. we wanted the extra just in case. does this sound OK? 12v AGMS
Sounds logical, my renogy 2000watt does great I'm in 3 100 ah lithiums
I just published a guide on calculating wires and fuses. Even if your inverter can draw 2,000W, you need to size for a 2000W power draw.
Small battery bank will have very short run times, AGM's are easy to kill very sensitive to charge voltages. The fuse is sized to protect the wire, not your devices, but with single aut you're fine with that fuse.
The 12V 100Ah Renogy AGM Battery you pictured far out paces your C-rate calc of 20A. It is rated at 30A with a 5 second rating of 100A! A couple of these tied to a 2000W inverter works wonderful in a typical RV.
It could deliver 1100A, but do that a few times and you will have a dead battery. Deep cycle gels or AGMs are not made for high current. Can they do it? Yes. Is it ideal? No.
No battery is good at high current. Geez, if makers would just get off of playing with the numbers trying to fool us to sell a battery. If you want high current, use super capacitors,@@cleversolarpower
the only time you would ever hit the battery with 1100AMPS would be with a big diesel engine lol @@cleversolarpower
@@NightshiftCustom Sorry typo. Should be 100A.
what about 3000 watt inverter, 12volt 3x 300ah lifepo4 batteries and 800 w solar panels? how do I remedy?
Whats the problem?
Well explained, can you send these formulas?
How long will it last usage wise
Thank you for the video and for the diagrams. I have been having trouble finding out and understanding this information, liked and subscribed!
Welcome aboard!
where does the 0.2c discharge rate come from? I have never seen that specified by a manufacturer.
I have seen a 0.1c charge rate for lead-acid batteries, which makes charging them decidedly slower.
It's specified in the datasheet of batteries. The capacity is mentioned in ah at a 20 hour rate. This is 0.2C. The manufacturer would list the capacitiy of their batteries at a 20 hour discharge rate. It's also known as C20. Check my video about C-rate.
@@cleversolarpower Yes, of course - the marketing term. They advertise 100AH at the 20 hour rate - *0.05C, actually.* That is only a measly 5 Amperes (continuous). However, it is not necessary to be this conservative. Otherwise, no one would be able to start their car in the morning.
What needs to be looked at is a series of curves. And decisions made on the trade off between capacity performance and the number of charge cycles over an acceptable lifetime.
If you discharge continuously at 100 Amps, you might get something like 70AH out of it, in much less than an hour. (Mfg. vary) but you wouldn't want to market it this way. And sure, you will get longer run time and longer life if you take it easy on the current demand. But most real-life loads (except heating) have an intermittent duty cycle.
So lets look at my conservative design. 3 pieces of 12v 105AH AGM batteries in parallel. I want to use 50% of that capacity, or 157 AH; or 1,800 Watt-hours (nominally). And I like the idea of limiting to 0.5C for discharge and 0.1C for charging. And that gives me slightly over 150 Amps. Well, the inverter I chose is 2000 Watts, which is 167 amps at full capacity. I like to de-rate the load to 80% which would draw about 133 Amps. I have no problem doing that 0.42C continuously down to 50% State of Charge (SoC), which should last for about an hour. Then of course making the battery happy by getting it fully charged again. I use a 30 Amp smart charger for this rig.
Also, with lead-acid chemistry, I have the headroom to support the full rated 4,000 watt motor starting capacity (inrush) current of 333 Amperes.
Thanks for the videos!
Cheers!
You are oversimplifying a bit. Its not how big your inverter is but more what load you will put on it. Also you should have larger inverter than you need for starting motors unless you buy a coil based inverter. I'm running a 24v 960ah LiFePO4 system using a 3000 watt inverter. My daytime load (highest) is about 1000W. After a couple of days of cloudy skies, my batteries are empty. I could really use a larger battery however I don't have the solar capacity to support it (3.7kw) especially during the winter months.
Thanks for your feedback. You have to size for the inverter, not for the load you attach to it. Startup surge power is a whole other topic that I can make another video about. It's impossible to mention everything in a short video.
What do you run that uses 1000 watts,heck that could be an AC…? All I know is my 100ah doesn’t cut it so getting two 12v 230ah bats.
@@cleversolarpower - No, you do NOT have to size for the inverter. You have to know your loads and size the inverter to easily handle those, without pushing it too hard. Then you have to size your battery storage and your solar array. You keep acting like you have to go 100% all the time on all of these components, and that is most certainly not how any of this works, or should work.
@@2hotscottpromany things: microwaves, coffee machines, split A/Con, toaster, air fryer, electric jugs can all use over 1000W each.
@@2hotscottpro May I ask what you are looking for to buy. My batteries degenerated very fast (see my comments here) and I'm looking for a replacement. As far as i can see the best option is lifepo04. I’m looking at the brand Li Time.
Have not installed yet I purchased a 3000 W inverter that will handle a 6000 W. I don’t recall the amount of time but it’s a start of it for starting large motors and things load.
Then you are better off with a low frequency inverter for inductive loads.
Something you could talk about is using busbars like in your diagram. I bought some aluminum 1/8 x 3/4 stock and cut it down to 6" with two holes drilled in it for battery connections on my lead acid setup. Seemed to work good. I want to go with copper for my lithium hookup but no one talks about it and it seems everyone expects us to make interconnect cables. They also talk about using the same size for all cables and it seems to me interconnect battery cables for a 48 volt doesn't need to be as large as the wires going to the inverter. Large cables to the busbars where all the 48 volt batteries connect to. Very good video, thanks and I liked it.
Good idea, I will put it on the list.
At 5:25 the setup shows 12 batteries? But doesn't the calculation formula you show say 3 batteries. 12volts x 4 = 48volts, and 100ah x .2 x 4 = 80amps...? Or is it when the batteries are wired to make the 48 volts the 4 together count as one and can still only output 20 amps?
Good question. Each battery should output a maximum of 20A. Less is better of course. So with 4 12V batteries in series each battery delivers 5.2A. We need 48V, to stay under (my recommended) 100A to keep the system correctly sized. You don't have to stay under 100A, it's just my recommendation for DIY off grid systems. I made a video similar to this one showing how many 12V batteries you need to have to run a 3,000W inverter.
What if you are only drawing 1800w from the 3000w inverter , does the inverter still draw as much current?
Thanks so much, I ordered the free diagrams. But one feedback: for some reason this video is blocked for saving to my solar power playlist for future replays and reference. Why have you blocked this option? Usually that option is only blocked for videos not suitable for children.
Thanks! I tried it and it seems to work fine for me. There is no option to prevent this from being possible.
Concise & to the point. This really shows how far lithium batteries have come. Thanks!
Im a bit confused i have a 2500watt mig welder max 90amp. Thinking about fitting a 3000watt inverter in my garage what battery would i need to run the above thanks.
What's the absolute top surge amperage when you create your spark, that could b well above 3k. Then you need to decide whether you want 48/24/12V batteries. Then you need to decide what chemistry you will use, lifepo4, lead acid, gel etc. Then you need to figure out your usage over time in order to size your array. There are many steps to take on your journey.
I always use my generator for welding. I'm running a 24v/3000w system. Welding impossible.
I just bought the power queen 12.8v 300AH battery and their 2000W inverter, do I need the 3000 W inverter? Or is 2K ok?
It depends on what your load is. If your load is larger than 2kW, then get the 3kW. If not, best to go as low as possible.
Can I use one battery of 120 have for 3.5 kVA inverter
I use 12v lighting in every room and 2000w inverter for frig and freezer. Supply power is 800w=8 amps solar 200w=2amps wind feading 6 lead deep cycle 780ah batteries. Now given we dont run all the lights and kids dont leave frig door open lol i can run for months without needing charged from normal means . I set my system up for backup only (just incase) but i know im good to go .
Off grid if need be
Absolutely brilliant information. I have got my own solar systems running, one being a 12v and another a 24v. However, I am trying to check how much can they handle, so that I can assign specific gadgets to each one of them - right now in the middle of testing. The fridge, kettle work and the slug wire trap system work OK, more things to add. Your calculations are excellent, this will definitely help know what to add where, as I plan to upgrade both system a bit.
Glad you like it 😃. Good luck with your system!
I have a 3000W inverter, to run it at full capacity I need 4 lithium batteries because I need 2 to make 24v and 2 alone can only give 100A at 24v which is 2400w, so I need 4 of them to be sure to have enough to run my 3000w inverter at full capasity. (it can also use 6000w for a short while but the batteries can also provide more Ampere for a short while so it balances out).
I like how I can go back over the information and get a little better understanding, I think calculating sun hours and number of panels will tell me what I can afford i.e what size will my offgrid setup cost which in turn will tell me what I can run, cheers mate
Glad it was helpful 🙂
Good information. I would add the DOD factor to point out the differences in the chemistry's
for a 3000w inverter can you use 2 x 12v 200 ah lithium batteries ? The calculation should be the same.
That would make it a 24V 200Ah battery. 3000W/24V=125A*1.25=156A It is possible, but I recommend using a 48V battery because of the mentioned benefits of having a higher battery voltage.
@@cleversolarpower - You don't have to connect them in series. You can have 2 x 12v 200ah batteries. Each will only deliver half of the needed amperage. That's still a lot of draw for a 3,000w inverter, but if you're using an inverter that large, you should have a larger battery bank, anyway.
@@jasonbroom7147 Indeed. But connecting in series will increase the diameter of the wire. Overall just having two batteries is not enough for a 3000W inverter like you said.
@@cleversolarpower - Since when has connecting batteries in series meant you need to increase the diameter of the wire? It is very common knowledge throughout the solar industry that you go up in voltage (which a series connection does) so you can use SMALLER wires, not bigger ones. I'm starting to get the sense that you are really new to this and don't actually know what the Helsinki you're talking about!
Something's off about the math on the diagram featured at 5:24 time stamp. It says to get 48v/300 amps to wire it in the sequence shown.
But each battery is 12v/100Ah so wouldn't it be 48v/1200Ah?
12v/100Ah x 4 would equal 48v/400Ah, and then multiply by 3 sets wired in series.
You don't choose wires based on the capacity (ah) of the battery. You size based on the current (a). You got these two confused.
@@cleversolarpower I'm not referring to the wires, I'm referring to the total amp hours at the top of the diagram.
It shows 4 batteries in series which by math 12v/100Ah would be 48v/400Ah. Plus there's 3 rows of that, which multiplied by 3 would be 48v/1200Ah.
Thank you for the clear video, I agree with its content but feel it slightly ignores a key dimension to this issue: it is mostly centred around the idea of running an inverter from a single battery only. In that case obviously higher voltages will fare better than lower voltages because they will require less current. But isn't it the case that you can supply the necessary input to the inverter within the relevant "C" constraints of your battery chemistry by adding more batteries in parallel. I am happily running a 3000W inverter using a set of six 24V (110AH) LiFePO4 batteries in my off grid cabin - at 3000W the total current is 125A but each battery is only discharging at a sixth of this because they share (equally, according to the bluetooth instrumentation they display) in the supply of that current. Did I miss something?
You are completely right. Having a larger battery is the best solution. Just like you did. I thought I made that point clear in the video 😅
@@cleversolarpowerSorry! I went through it all again and saw you did make that point in the lead acid section.
This is by far the best explanation I have heard. New sub, thanks for your very informative vid!!
Thank you!
G'day man love your show. I have a question if you don't mind. I'm getting a portable block Redarc install in my vehicle it does not have an inverter so watt power inverter should I get I would appreciate your help Dave
I dont know what a redarc is, but i assume it's a battery with some usb chargers,... It depends on the BMS inside, some have a 100A BMS, some less. It should be in the datasheet of the product you got (the redarc).
So how long will these batteries last as far as operation in hours under these loads? 1 hour 2 hour no mention.
I use deep cycle marine batteries and I have a way to get more.. you can't have too many batteries in parallel it just takes longer to charge
I loved the video. Maybe someone has already said something, but I think I see an error. At 4 minutes & 42 seconds in the video on the "Lead Acid Battery Example" it shows 3 lead acid batteries instead of 4. Making it 36 volts, changing the breaker to a 83.33 AMPs. Maybe you meant 4 Batteries. Otherwise, I am thinking this would mess up the calculations and burn out something? I would like to know for sure. Thank you.
It's a minimum of 3 batteries. That would indeed make a 36V battery system, but our inverter works on 48V. So we have to increase it to 48V and then we have 4 batteries in series.
Solar panel disconnect switch before solar charge controller or after?
Before. So you can safely work on the system without power feeding into it. Technically, you can have disconnects between all components, to ensure you can work on any part of the system without worry. Disconnecting power from the solar panels will not isolate or disconnect power between your battery and inverter. Most people only have a fuse between the inverter and battery, but some will use a breaker, so they can switch off the power from the battery to the inverter.
i have 3000w inverter running of a 12v lithium battery 300amp what size fuse do i need. cheers
I use 3 x100 A.H. Lead Acid batteries for a 12 Volt 3000 Watt sine wave inverter..it runs an 800watt Inverter with ease.
Depends on the size of the battery, and the voltage you are starting from. I never advise to go above 3000w from 12 volts
Yes, max 2000W for a 12V battery if you are in an RV, and max 1200W for normal system.
Hi sir, does it mean that a 3000watts 24v inverter is not advisable setup? Cause doing the computation it will produce 100+ amperes. Can you confirm?
Can you please give information on how many batteries needed for a 12v system on a commercial truck to run a 3000 inverter
The 80A fuse you recommended, is that the AC fuse for the Inverrer? If yes, don’t you think that would be too much, especially, with a lead acid battery setup, considering that you would only be pulling and also charging at a current just around 20% of the battery capacity rating, per hour?
It's the DC fuse.
I have 700 watts of solar, two 206 AH lithium ion batteries and a 3000W inverter in my camper. It works great. I can run the AC for short periods of time but i prefer to use a generator for that. I'd like a bit more solar and a third battery so I'm covered for winter, but that's a ways away. I'm out of room on my roof so that's one problem.
I have 6 100W panels, 2000W inverter, Lithium Ion 300AH 12.8V, and 120A Charge controller, ....by. your calculation, 2000/12.8 = 156 A .... will the Amp load be too high? do I need to buy another 300 AH battery and wire it in a series in order to lower the amp load? if I hook it up as is will it explode
OHHHH the LOAD of 156 Amps has to be lower than the C RATE I get it so the C rate is 300 so 156 < 300 AH so I think im good right?
That is correct. You are good.
How can I give estimate for 4 panels solar of 250w
Excellent information. Thanks.
Thank you for the video. How about a practical example in the end? Like with the 48v 100amp hour, how many hours can I run a 15 amp window ac unit and how long to recharge with a generator like off grid or during a power failure scenario. I appreciate the math, but I need to know run times and re-charge for better context.
Very excellent description indeed
How do you ground the inverter system?
I have a video about that coming up. But it's complicated so it takes longer 😄
What I mean is should I use two batteries to run a 1500w inverter to run a 1500 w heater in my truck. And if so do I hook it up in set. Or in parr.
Only use one inverter. If it's higher than 1000W, then get a single 24V 100Ah battery.
We have a 3000w inverter. Would 3 x 100Ah lithium batteries be okay to power this?
Quick question wouldn't it be helpful to hook up a trickle charger to keep from running down the batteries
Yes, always useful if you leave the batteries unattended for a longer period of time, especially lead-acid.
I just bought a new 3000va ups, it provides a voltage 163 to 190 volt , is that normal ?
What ampere should a 3000va ups deliver?
Doesn't seem like thats normal.
How can you put pure sinusoid inverters in paralel?
Thanks for the suggestion, video coming soon.
I have a question about inverters and batteries. I’m renovating my caravan with 240v wires throughout. I only plan to run a fridge, convection oven, lights and a tv and dvd player. The fridge will be the only one running non stop (while travelling around). The fridge is 240v 50Hz
0.73A 106W. How do I work out what size inverter and battery do I need?
I advice against a convection over. It draws a lot of power. For the fridge, multiply the power consumption by 8 hours, which is a 30% duty cycle. 106W*8h=850Wh I made a video about system design, look it up on my channel page.
How easy is it to find a 20A Charge controller with a maximum PV input voltage that is high enough to accomplish 800W of solar array?
It depends on the voltage of the panels and the max input voltage of the controller. Check my video about sizing a charge controller.
If I have a 3000watt inverter with 200ah lithium batteries what size fuses should I be using?
Check my video about wire and fuse sizes.
We have an alternator of 12v in a van vehicule, how can we install a system working at 24V or even 48V in order to be below 100A when requering high power, such as 3000 W and higher. I do not have clear how to charge the batteries using the van alternator. Many thanks
If you want to charge with your alternator I recommend 24v systems. I haven't found any DC to DC charger that is 12-48V. I have a video about different voltage systems in a few days. You would have to sacrifice some efficiency using higher than 100A, it will be more expensive, but in an RV this is what I recommend. Recently I installed a 24v 280ah battery in an RV.
@@cleversolarpower Many thanks for your prompt answer, I fully agree. Can you recommend any buck boost to increase de voltage from 12v to 24v in a RV? I am facing some problems to find one with enough power at a reasonable price.
to me there is no reason to run a 24v or 48v on a rv at all stay 12v and just get a big battery bank at 12v then you can get a 200-370 amp high output alternator if needed and can get a few solar panels on your roof in most cases
on a RV you have all short cable runs and very small space for solar panels so there is not need to to go with a higher voltage system at all and they make lots of 3000 watt 12V inverters for this reason as that all you would ever need in a RV also can charge very fast with the engine running and run everything at full load no problem
I would love some help picking the right inverter for my f350 @nick. I have two lipo batteries under the hood
take the C-rate of the battery and multiply by the capacity. if each battery has 0.5C discharge rate and is 12V 100Ah, then you become: 100Ah*0.5C*2 batteries= 100A max discharge. 100A*12V=1200W inverter maximum.
@@cleversolarpower thank you so very much. How can I buy you a beer?
am i really the only one who just cannot grasp all this?
I'm going quick in this video, so watching it a second time might be better. To simplify: 1. increase the voltage so that the current is limited to 100A (not necessary but good for sizing) 2. increase the capacity of the battery so that the C-rate of the battery type is respected.
No...😂
No….
No joke to me over 10 years of slowly learning for it to finally click
No I just want to know how many to power 2,000 watts
Please have you get branch selling products for Nigeria
I don't sell products.
Sir i have solar panel that has 100watts and 12v 100ah battery with inverter of 600w-1200w
But when i try to charge my laptop... battery finishes fast and inverter starts to make the annoying noise,what can i do to fix that problem?
We have 4 - 200 amp hr ion lithium batteries running 12 V with a 3000 W inverter. will be switching over to 24 V I don’t need a 3000 W inverter so is it better for me to run a 2000 W inverter with a 24 V system?
If you already have one running, then switching over to 24V is not necessary. Should be done in the design phase.
The Renogy 3000 w inverter shown in your video is only for 12V systems. I am so confused.
That's the point of this video, that you should not use a 3000W inverter with a 12V battery.
@@cleversolarpower so don't get the renogy 3000 watt inverter?
How do you feel about the new watt cycle 12v 300ah mini battery?
I haven't seen the inside of a 300Ah. Will Prowse did a review of the 12V 100Ah and it seemed to be fine.
thank you i was abit in the dark now i can see the light i am more confident to start purchasing my batteries and inverter
No problem! I will publish a video about a 1000W inverter soon. The same principles apply, and I tell why we size this way in that video.
@@cleversolarpower sorry to reply only now, I purchased a luxpower 48v 5kw and AND a 5kwa battery I forget the name, I had it installed and I AM very happy it's like a power station all on its own and bcos of the inverter I changed to gas where alot of power is needed so I don't fear the power going off anymore I feel protected
i need help with my 4000w inverter what are the best batties to use
For a 4000W inverter, you should have a 48V battery.
Help!
I have 300 watt running into a solar connector. Those then output to a 500 wat charge controller. From there I have the charge controller running into a battery. The battery is attached to a 2000 watt inverter.
Am I safe or do I need to adjust anything? Heard the fan kick on.
It's safe. However, depending on the battery size, your inverter can be oversized. This is not bad, it just doesn't go together like mentioned in the video. Assuming you have sized the cables and fuses correctly. Fan kicking on is normal.
I'm trying to figure out the optimal set up for my Freightliner Cascadia transport truck that runs an electric APU with an inverter inside the bunk to power electronics. The inverter is 2000w but I'm not sure if it could handle a 5000w inverter
What is the best way to contact you?
Most of the times it will work, but that does not mean it's correctly sized. As you can repeat the calculations in this video for your own use case. You can send en email to me through my website cleversolarpower.com
What battery capacity is needed for running 250watts refrigerator
250W*8hours (33% duty cycle)=2000Wh 12V*100Ah=1200Wh, so at least two 12V 100Ah batteries.
How would I set up 2 24V DC batteries for a 3K W inverter ? Parallel?
Depends on the voltage of your inverter and the Ah of the battery. Check the calculations in the video.
Your inverter sets the systems design voltage
Totally new at this but I want to build a system to run 2 freezers for emergencies.
Don't need solar to recharge since I have a gas generator to recharge with.
This is all for emegency backup and I would build a separate one for a refrigerator.
You can do it easily. You have to figure out the consumption of the 2 freezers and then multiply by the amount of days you want to run them (usually 3). Then add a charger and inverter. 3000W should be enough, and I recommend using a 24V system for this.
Thank you@@cleversolarpower
Great information! I build solar systems and you taught me some things!
So, to simplify, you recommend a lithium battery should be sized to have sufficient capacity (in Watt hrs) to run at the inverter's full power for 1 hour, or 5 hours for lead acid batteries.
Very good explanation i have 5000 watts inverter how many batteries do i need and like wise solar panels and controller
Gines
Hi Gines, You can repeat the calculations for your 5000W inverter.
Any battery recommendations for off grid, for a 4000w inverter and 4000w solar panel ?
I recommend a 48V server rack battery.
How long do you need to run for in KwH with out that nothing can be said, and then what system voltage. I usually recommend lead acid for beginners as it is more forgiving of mistakes, then by the time that bank dies you should have saved enough to buy lithium for your more permanent bank. and the type of lead acid I recommend is Flooded traction battery (True deep cycle)
Where do you get the 48 volts to charge?
4 Connect the 4 100 watt 12 volt solar panels in series. You get 400 watts available at 48 volts.👍
By the way be sure your charge controller can handle the voltage from the solar panels.
When you refer to Lead Acid batteries are you also referring to AGM Absorbed glass matt or Gel batteries also, as I understand they have quite differing characteristics to conventional 'wet cell' Lead acid batteries, ie less resistance, larger charge rates and deeper cycling 50%
sorry continuing :deeper cycling 50% than a conventional wet cell battery at 20% discharge safely for maximum lifespan.
AGM or Gel batteries obviously have more capacity than conventional wet cell
L/A's.
Yes, I'm referring to all lead acid battery chemistries. Which wet cell battery can you discharge to 20% without impacting it's lifespan too drastically?