🛒 We Recommend Shopping At: • Signature Solar: signaturesolar.com/?ref=thesolarlab • Use Code: THESOLARLAB50 for $50 Off Your Order • Shop Solar: shopsolarkits.com/?ref=TheSolarLab • Use Code: THESOLARLAB50 for $50 Off Your Order 🤓 Watch the rest of the videos in this playlist: ua-cam.com/play/PL23_m8HBj7OJQSt1fGveO_rQgn4-zYBB0.html 0:00 - Intro 0:29 - 60 Second Electricity Lesson 1:39 - 12V Batteries 3:06 - 24V Batteries 3:53 - 48V Batteries 5:31 - Summary Curious about the differences between 12V, 24V, and 48V batteries for your solar power system? In this video, we break down the pros and cons of each voltage, how they affect performance, cost, and which one is best for your setup. 🔔 Subscribe to our UA-cam Channel: @TheSolarLab ⚡ FOLLOW US: instagram.com/thesolarlab/ www.tiktok.com/@thesolarlab 👨🏼💻 The Solar Lab: www.thesolarlab.com We maintain an affiliate relationship with some of the products reviewed, which means we get a small percentage of a sale if you click our links, at no cost to our viewers.
Also charge controllers are far more effective at 48V than at 12V. A 20A charge controller at 12.8V can handle up to 256W worth of solar panels. That SAME controller at 51.2V can handle over 1000W (assuming a controller that does 12/24/36/48V of course, but many do these days). Just as an example. Convenient kitchen appliances... Microwave, induction tea kettle, toaster oven, induction "burner", well pump.... the list goes on. Best to just go straight to 48V (51.2V LiFePO4) in most situations. In fact, I would only consider 12V at far lower wattages than the channel recommends. If its less than 500W then 12V is an option. If its more, or you might scale higher than 500W, then I'd go straight to 48V. At 48V, 2 AWG main battery and inverter wiring nets you 100A @ 51.2V = 5000W of continuous power without anything even getting warm to the touch, let alone hot. And all the solar panel string and charge controller output wiring can be 10 AWG. The only real gotchas with 48V is that (A) You need to be a bit more up on your electronics skills. (B) Getting any fusing and breakers right is more important. And (C) you need to pay more attention the solar panel topology. The best charge controllers are buck controllers (Victron's for example) which means that to work properly with a 48V system the solar strings have to generate roughly 65VDC or higher "operating voltage". --- For string voltages I shoot for at least 70V. Higher if partial shading might be an issue. My go-to charge controller is thus something like a Victron 150/35 for the voltage range it supports rather than a Victron 100/20. A single 150/35 can handle 1800W worth of generation all by its lonesome. You can do this with any solar panel wattage but you need to figure out how many in series you need to get decent results, plus one more to help deal with partial shading situations. Even 25W panels would work, but you would need 4 x 25W in series to develop a decent voltage for a 48V system. Similarly for other small panels. When you get to more serious panels... 100W you typically need 3 x 100W in series (but if they are low-voltage 100W panels you'd still need 4). 200W panels you would also typically want 3 in series. Higher than that the voltages are higher so typically residential panels would need only 2 in series. My go-to is always 48V. I only consider 12V for very very small systems and only consider 24V in very special cases. My default is 48V these days. -Matt
Finally, thank you!✌️ I've been looking at systems for a trailer build with AC! I don't want an AC that relies on a generator! Seems the 48volt is the wisest and most efficient way to go!👍
My thoughts exactly, I travel and work out my RV for months at a time, often without electricity connections for days. In the south like Texas, that turns into a hell like situation in the summer.
I built my system back in 2020 48v components were hard to find and expensive. Back at that time Will Prowse was recommending 24v system for medium system like my 250 square ft cabin. I bought a Big Battery 24v 170ah lifepo4 ,2000w inverter and 1000 watts of panels. I use it about it about 120-150 days a year and I'm using the exact system I started with and no down time.
What about safety considerations for the beginners that this video seems aimed at? Is it much easier to get yourself in trouble/danger handling 48V stuff? What are the most important safety cautions for the beginner? If that kind of info isn't in that playlist you mentioned, perhaps it would be a good candidate for another video.
Like getting hurt wise everything under 60volts is pretty much the same level of safety. Starting fires type safety the voltage really doesn’t matter 12v will burn down a house just as good as 480v.
The functional difference is that the 4 x 12V (12.8V LiFePO4) batteries in series are far, far less reliable than 4 x 48V (51.2V LiFePO4) batteries in parallel for the same storage capacity (assuming all else is equal and the batteries have the same storage capacity in watt-hours). For example, 4 x 51.2V 50Ah LiFePO4 batteries in parallel is comparable to 4x 12.8V 200Ah LiFePO4 batteries in series. Same weight, same overall capacity, but vast differences in reliability. -- * When you have four 12V batteries in series you need additional wiring for a whole-battery balancer to keep the four batteries balanced. Also, if you ever hit a LVP or OVP situation and cause one or more of the batteries to disconnect, it can actually take some effort to wake it back up. (when batteries are in parallel, they recover automatically from such disconnects, but not usually when they are in series). * Also, most people are going to have more than one battery and paralleling batteries adds a lot of redundancy. It is better to have (for example) 4 x 48V batteries in parallel than it is to have 4 x 12V batteries in series. * It is easier to scale the higher-voltage system because you only need to add one battery at a time whereas with several batteries in series you have to add N batteries at a time to scale-up your system. So with LiFePO4 while you CAN put batteries in series to generate the higher voltage, and doing so appears to work well at the beginning, it is not ideal and has a lot of potential problems. Unless you are retro-fitting an older system, you really want to use the proper native voltage battery to construct the system. -Matt
It seems like your animation and the way you described watts might be out of sync. Watts are Joules per second. Saying it’s like the total water in the bucket is not quite it. Like your animation, watts are more like how much water travels out of the hose in a second. The amount in the bucket is Joules or watt-hours.
Odd question… I want to boost my RV’s capacity as I use PC, Monitors, NAS, and other 120v devices like AC for months while traveling. What about inverter drain on a 48v system? I’m guessing that in addition to a step up inverter, I would also need to have a step down inverter too, as the 12v RV systems, refrigerator, lights, etc. run that. I know that I’ve powered everything down for the night and forgotten to turn the inverter off, and the drain is noticeable by morning. Does a 48v system require an inverter to be on 24x7 for the 12v RV systems?
No, inverters generate AC power. 48VDC to 12VDC does not use an inverter. You use a DC-DC converter though my recommendation for RVs is to have a DC-DC (48V to 12V) DC-DC charger instead of just a converter. With a DC-DC charger you add an additional 12.8V LiFePO4 battery on the 12V side. These are called "downbuffers". This helps a lot because then the charger only has to trickle-charge the battery (relatively low amps) while the battery sources all the power necessary to run the 12V systems... which depending on what you are running, such as auto-levlers and slides, might need a hundred amps to get going. The second reason for using a downbuffer battery setup instead of just a DC-DC converter is that any sort of failure between the 48V and the 12V busses will blow a fuse instead of putting 48V on the 12V bus and destroying all your 12V equipment. -Matt
I can 2x this information. Don’t waste your time with 12v or 24v. Just go straight to 48volt batteries and inverters etc. If you need 12volts then use a step down converter from 48v to 12v. The options for 48v stuff is huge compared to 12v. JUST GO WITH A 48VOLT SYSTEM!!!! DONT WASTE YOUR TIME AND MONEY. like me…. “Oh my rv and lots of its stuff is 12v so I’ll just buy a bunch of solar panels(6-200 watt) and 15kwh of 12v eg4 batteries and just a little 2000watt inverter to run my fridge 100% in a hurricane or if the power goes out.” Flash forward 7 months. “Man, I can fit like 11 more solar panels on my roof and prolly get rid of my generator and add 3 more batteries and then prolly power 2 air conditioners with all that solar. Oh goddamnit I need 0000 size cables and I can only get 3kva inverters and now I need 2 and gotta put them in splits phase and get a lynx distributor and more cables and. Fuck!”
1. A 120V battery could kill you; 120V DC is more likely to electrocute you than 120V AC, because the latter crosses zero 120 times a second. 2. You’d still need an inverter to power your AC appliances, so 120V DC doesn’t have a ton of benefit. 72V batteries are fairly common, but are also more likely to electrocute you than 48V. 50V DC is right around the threshold of “it might kill you, it might not”. 120V DC is well in the “it’ll probably kill you” territory.
@jimothy4j Yes, Nicola Tesla figured all this stuff out first!! He is the goat. Thomas Edison was a charlatan/business guy taught to us in elementary school.
🛒 We Recommend Shopping At:
• Signature Solar: signaturesolar.com/?ref=thesolarlab
• Use Code: THESOLARLAB50 for $50 Off Your Order
• Shop Solar: shopsolarkits.com/?ref=TheSolarLab
• Use Code: THESOLARLAB50 for $50 Off Your Order
🤓 Watch the rest of the videos in this playlist: ua-cam.com/play/PL23_m8HBj7OJQSt1fGveO_rQgn4-zYBB0.html
0:00 - Intro
0:29 - 60 Second Electricity Lesson
1:39 - 12V Batteries
3:06 - 24V Batteries
3:53 - 48V Batteries
5:31 - Summary
Curious about the differences between 12V, 24V, and 48V batteries for your solar power system? In this video, we break down the pros and cons of each voltage, how they affect performance, cost, and which one is best for your setup.
🔔 Subscribe to our UA-cam Channel: @TheSolarLab
⚡ FOLLOW US:
instagram.com/thesolarlab/
www.tiktok.com/@thesolarlab
👨🏼💻 The Solar Lab:
www.thesolarlab.com
We maintain an affiliate relationship with some of the products reviewed, which means we get a small percentage of a sale if you click our links, at no cost to our viewers.
Also charge controllers are far more effective at 48V than at 12V. A 20A charge controller at 12.8V can handle up to 256W worth of solar panels. That SAME controller at 51.2V can handle over 1000W (assuming a controller that does 12/24/36/48V of course, but many do these days). Just as an example.
Convenient kitchen appliances... Microwave, induction tea kettle, toaster oven, induction "burner", well pump.... the list goes on. Best to just go straight to 48V (51.2V LiFePO4) in most situations. In fact, I would only consider 12V at far lower wattages than the channel recommends. If its less than 500W then 12V is an option. If its more, or you might scale higher than 500W, then I'd go straight to 48V.
At 48V, 2 AWG main battery and inverter wiring nets you 100A @ 51.2V = 5000W of continuous power without anything even getting warm to the touch, let alone hot. And all the solar panel string and charge controller output wiring can be 10 AWG.
The only real gotchas with 48V is that (A) You need to be a bit more up on your electronics skills. (B) Getting any fusing and breakers right is more important. And (C) you need to pay more attention the solar panel topology. The best charge controllers are buck controllers (Victron's for example) which means that to work properly with a 48V system the solar strings have to generate roughly 65VDC or higher "operating voltage".
---
For string voltages I shoot for at least 70V. Higher if partial shading might be an issue. My go-to charge controller is thus something like a Victron 150/35 for the voltage range it supports rather than a Victron 100/20. A single 150/35 can handle 1800W worth of generation all by its lonesome.
You can do this with any solar panel wattage but you need to figure out how many in series you need to get decent results, plus one more to help deal with partial shading situations. Even 25W panels would work, but you would need 4 x 25W in series to develop a decent voltage for a 48V system. Similarly for other small panels. When you get to more serious panels... 100W you typically need 3 x 100W in series (but if they are low-voltage 100W panels you'd still need 4). 200W panels you would also typically want 3 in series. Higher than that the voltages are higher so typically residential panels would need only 2 in series.
My go-to is always 48V. I only consider 12V for very very small systems and only consider 24V in very special cases. My default is 48V these days.
-Matt
Finally, thank you!✌️
I've been looking at systems for a trailer build with AC! I don't want an AC that relies on a generator! Seems the 48volt is the wisest and most efficient way to go!👍
No problem! Yes, it sounds like 48V system would be your best option ⚡️
My thoughts exactly, I travel and work out my RV for months at a time, often without electricity connections for days. In the south like Texas, that turns into a hell like situation in the summer.
@TheSolarLab
There will be a 3000 inverter, but what's needed for 12-volt needs, i.e., refrigerator and USB needs....!?
now this is a good video explaining voltage.
could never understand voltage but now i do.
48V is the way to go! Nice vid, thanks.
Thanks for watching ⚡️
I built my system back in 2020 48v components were hard to find and expensive. Back at that time Will Prowse was recommending 24v system for medium system like my 250 square ft cabin. I bought a Big Battery 24v 170ah lifepo4 ,2000w inverter and 1000 watts of panels. I use it about it about 120-150 days a year and I'm using the exact system I started with and no down time.
Excellent vid. Thank you. I'm just starting my list. so 48v to start. What's next? I have a 900 s/f home.
What about safety considerations for the beginners that this video seems aimed at? Is it much easier to get yourself in trouble/danger handling 48V stuff? What are the most important safety cautions for the beginner? If that kind of info isn't in that playlist you mentioned, perhaps it would be a good candidate for another video.
Like getting hurt wise everything under 60volts is pretty much the same level of safety.
Starting fires type safety the voltage really doesn’t matter 12v will burn down a house just as good as 480v.
One caveat to your skip 24V statement is if your setup is running DC load components w/o an inverter.
Thank you For These Videos. I Learn A Lot
No problem! We love to hear it ⚡️
Thank you very much for the comparison explanation. You do great videos and give excellent advise. 🙏🏿👍🏿
Glad you find them helpful!
What's the functional difference between 4 12-volt batteries wired in series and a 48-volt battery composed of 16 3.2-volt cells?
The functional difference is that the 4 x 12V (12.8V LiFePO4) batteries in series are far, far less reliable than 4 x 48V (51.2V LiFePO4) batteries in parallel for the same storage capacity (assuming all else is equal and the batteries have the same storage capacity in watt-hours).
For example, 4 x 51.2V 50Ah LiFePO4 batteries in parallel is comparable to 4x 12.8V 200Ah LiFePO4 batteries in series. Same weight, same overall capacity, but vast differences in reliability.
--
* When you have four 12V batteries in series you need additional wiring for a whole-battery balancer to keep the four batteries balanced. Also, if you ever hit a LVP or OVP situation and cause one or more of the batteries to disconnect, it can actually take some effort to wake it back up. (when batteries are in parallel, they recover automatically from such disconnects, but not usually when they are in series).
* Also, most people are going to have more than one battery and paralleling batteries adds a lot of redundancy. It is better to have (for example) 4 x 48V batteries in parallel than it is to have 4 x 12V batteries in series.
* It is easier to scale the higher-voltage system because you only need to add one battery at a time whereas with several batteries in series you have to add N batteries at a time to scale-up your system.
So with LiFePO4 while you CAN put batteries in series to generate the higher voltage, and doing so appears to work well at the beginning, it is not ideal and has a lot of potential problems. Unless you are retro-fitting an older system, you really want to use the proper native voltage battery to construct the system.
-Matt
The 4 12v systems have 4 individual BMS. Better hope they're compatible. The 48v system is more compact (space efficient) and has one BMS
FINALLY……someone illuminated volt, amp and watt in a way my tiny mind can see!
It seems like your animation and the way you described watts might be out of sync. Watts are Joules per second. Saying it’s like the total water in the bucket is not quite it. Like your animation, watts are more like how much water travels out of the hose in a second.
The amount in the bucket is Joules or watt-hours.
Odd question… I want to boost my RV’s capacity as I use PC, Monitors, NAS, and other 120v devices like AC for months while traveling. What about inverter drain on a 48v system? I’m guessing that in addition to a step up inverter, I would also need to have a step down inverter too, as the 12v RV systems, refrigerator, lights, etc. run that. I know that I’ve powered everything down for the night and forgotten to turn the inverter off, and the drain is noticeable by morning. Does a 48v system require an inverter to be on 24x7 for the 12v RV systems?
No, inverters generate AC power. 48VDC to 12VDC does not use an inverter. You use a DC-DC converter though my recommendation for RVs is to have a DC-DC (48V to 12V) DC-DC charger instead of just a converter.
With a DC-DC charger you add an additional 12.8V LiFePO4 battery on the 12V side. These are called "downbuffers". This helps a lot because then the charger only has to trickle-charge the battery (relatively low amps) while the battery sources all the power necessary to run the 12V systems... which depending on what you are running, such as auto-levlers and slides, might need a hundred amps to get going.
The second reason for using a downbuffer battery setup instead of just a DC-DC converter is that any sort of failure between the 48V and the 12V busses will blow a fuse instead of putting 48V on the 12V bus and destroying all your 12V equipment.
-Matt
I can 2x this information. Don’t waste your time with 12v or 24v. Just go straight to 48volt batteries and inverters etc. If you need 12volts then use a step down converter from 48v to 12v. The options for 48v stuff is huge compared to 12v.
JUST GO WITH A 48VOLT SYSTEM!!!! DONT WASTE YOUR TIME AND MONEY.
like me….
“Oh my rv and lots of its stuff is 12v so I’ll just buy a bunch of solar panels(6-200 watt) and 15kwh of 12v eg4 batteries and just a little 2000watt inverter to run my fridge 100% in a hurricane or if the power goes out.”
Flash forward 7 months.
“Man, I can fit like 11 more solar panels on my roof and prolly get rid of my generator and add 3 more batteries and then prolly power 2 air conditioners with all that solar. Oh goddamnit I need 0000 size cables and I can only get 3kva inverters and now I need 2 and gotta put them in splits phase and get a lynx distributor and more cables and. Fuck!”
Why does no one make a 120v battery?
Easy to make, a little tougher to carry though.
1. A 120V battery could kill you; 120V DC is more likely to electrocute you than 120V AC, because the latter crosses zero 120 times a second.
2. You’d still need an inverter to power your AC appliances, so 120V DC doesn’t have a ton of benefit.
72V batteries are fairly common, but are also more likely to electrocute you than 48V.
50V DC is right around the threshold of “it might kill you, it might not”. 120V DC is well in the “it’ll probably kill you” territory.
@jimothy4j Yes, Nicola Tesla figured all this stuff out first!! He is the goat.
Thomas Edison was a charlatan/business guy taught to us in elementary school.
You are clearly living true to your ideal. Thanks for your explanations. (DoMore)
Great info…. Thank you
Thanks for watching!
Good info.
Glad you found it helpful!
Super useful video
Glad you found it helpful!