Get more flight time with a DIY lithium-ion battery
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- Опубліковано 11 гру 2022
- Whether you fly a drone or RC plane, using a lithium-ion battery instead of a lipo can give you more flight time and, if you build your own, even save you money. In this video I build a 6S Li-Ion battery using 21700 cells and take it for a test flight on the Foxeer Aura 7 quadcopter where it delivers 20 minute flight times.
Links (not sponsored or affiliate):
Where I got the batteries : 18650batteries.nz/
The Foxeer Aura 7 BNF long-range quadcopter:
www.foxeer.com/foxeer-aura-7-...
A huge thanks to those who support me on Patreon and thus free everyone from the tyranny of sponsorship segments, mid-roll ads and affiliate links.
/ rcmodelreviews - Наука та технологія
Fuck Parkinson's! I really appreciate all your videos over the years Bruce. And your still fighting for the hobby, much love.
Hi Bruce,
Great method to soldering L-ion batteries. Nice flight. Glad the spool of solder I sent is still going strong. I think that was 4 or 5 years ago. You and your family stay safe.
Thanks again for that!
I think that makes that solder more legit than this "So Called UA-camr"
Wink, lol
Glad to see you're still making videos. Awesome.
The Molicel brand is my go-to for these builds. Their 21700's, especially, deliver a wallop or capacity and performance for the price!
Yep, my fav LR pack I've built. Did 10 miles on my endurance 7"
Agreed, I use Molicell 21700 too and they work brilliantly. 4S on a 6inch with 20+mins flight time
Yes they do I bought 50 of them and made 3 6s packs for my fms super scorpion and futura I run them in parallel to get either 8400mah to 12600mah
Same here. Molicell 21700 ftw.
Molicell P42/45B has the most current of the 21700 batteries. Other batteries like the Samsung 50S or LG 58T has less current but more energy (Wh)
You are awesome. I always learn from your videos. Have a great Xmas/ holiday season. Thank you
This was awesome Bruce! Thanks and Happy Holidays! Cheers
YAY delivering the goods! Thank you!
I also await the video about long range antenna placements! Thank you!
Entertaining, and informative. Thank you Bruce!
Happy Christmas 🙏 Thanks for everything 😀 ☺️🤠
Great stuff as usual Bruce.
nice video but you kind of skipped over how to install the balance lead, i am pretty sure a lot of people need help with that too! youre a legend keep up the great rc videos mate
yeah, I'll possibly do another video on that.
@@RCModelReviews That would be great. And cover what type of charger is required please.
@@RCModelReviews please do, eager to solder my own battery. Thanks for the lecture, really liked your old video’s where you educate technically. Greetings from freezing Netherlands
I made an tutorial on my channel some years ago. You can take a look if you want.
Great video very well explained, going to make one for a long range 6 inch drone.
Wow, the sky there looks beautiful!
hi omni_ have you become a flat earther yet?
Watched it again... awesome!
Thanks for sharing merry Christmas and happy new year
If I remember correctly, the name of that video that got me in deep financial trouble with the Wife is “Lead Free Solder Sucks!” Way back in the ZMR 250 era. Still valid today. Great stuff Bruce!
Awesome video Bruce.. I've never watched a battery SODERED together.. were lazy here in the USA we just buy them.. lol.. .. all kidding aside I learned a ton THANK YOU.. 💙💙👍👍
MIKEY
In the USA and I have 20 ish home built Molicel packs.
But I did immigrate from Vietnam, so I guess the laziness comment could be true, lmao
These won't replace a LiPo for current req, yet, but they're soooo good for less sporty airplanes and most cars
Excellent video, Bruce! Thanks for all the tips! 😃
I already built some of those packs, but now I'm seriously thinking about getting a cheap spot welder from China...
Anyway, stay safe there with your family! 🖖😊
I've built a 6S pack with the same type of cells. But I put them in a row instead. I added heat shrink at each pole, like a cap. I don't trust that thin plastic film around the cell. Adds some space between the cells which in theory could help with cooling. Use a large tip just like Bruce says and some quality flux. Have the window or balcony open to throw the stuff out if you mess up! Remember to protect exposed leads unless you like blinding flashes. Flown them on 8 inch frames with moderate current draw. After a flight they come down lukewarm.
Thanks #rcmodelreviews didn’t know I had to check volt between the balance wires saved me a House 😂
This is great. I built a lion pack for my rc car about a year ago. I only needed 2s for the car but made a 2s2p pack of 4 sony vtc 6 cells (30 amp rated) the 2p configuration divides up the current draw so they dont work as hard. On a car, the runtime is well over an hour and they never even get warm. They fit right in the battery tray. I also use them in my 1/16 rc tank. Work great and no typical lipo worries like storage charge or low voltage. I think I use 3v as my low voltage alarm but have only seen it happen once since building. I usually get finished and put the toys away before the pack ever runs out. FYI, in Canada anyway, a great way to get lion cells is the vape shops that are literally everywhere these days.
I love the potential for long flight times. My old 1100gram, 10inch 450 style quad used to get 26 minutes on a 3s 6400mah lipo pack.
Imagine that pack in a plane! You could fly forever!
Cheers.
Hey Bruce long time hope your well and your family wish you a Merry Christmas and Happy New years. God bless you and your family.
That's useful information Bruce, but I would find it hard to justify on cost grounds in the UK as lipos actually seem to be more cost effective. The Lions seem to be a lot cheaper over your way but 6 21700s cost around UK£70 whereas a 6S 4000mAh lipo can be had for as little as UK£65 or less if you buy multiples (£120 for 2). I've flown my 5-inch on a 5000mAh 4S before and got a good long flight time out of that, it did fly a bit like a brick though, you wouldn't be doing freestyle with that ;-) Anyway I don't know that its worth faffing around with Lion cells when the lipos seem to be cheaper.
Hi Bruce, using a separate flux will help the solder flow, also a wider tip will help you. Steve. UK.
If you're using a good quality (flux-cored) solder and have prepared everything properly (ie: cleaned it) flux isn't really needed. I have never used flux for this sort of thing, only for PCB work.
You don't need the 'L' in America - that cracked me up Bruce! Thank you. Hahahaha
Very good 👍
So easy and cheap to make your own Lion packs.
I would recommend getting a battery welder instead of soldering them. It can be done as you demonstrate, but you risk damaging the cell.
My welder is 220v, my soldering iron runs on 6s. Because the only 220v outlet I have is in my laundry room, I'm embarrassed to say it's only slightly used.
Anyone wanna buy a very slightly used Spot Welder for Liions? CHEAP!
Hi again Bruce, the cleaner the better, but using flux it helps to clean the cable and because the solder flow's quicker less heat is transferred into what you're soldering. When I was into electronics's I never used flux. Steve. UK.
Fantastic and awesome Bruce! I hope you are doing well. Your videos are always too much learning rich :) xD. I have started flying edf jets a couple of weeks ago and I´m thinking of building a 6S LiIon lipo since I enjoy soldering and love batteries. I already have too much lipos so I should give it a try. I normally fly with and 3300 which is around 50-60g heavier than yours. I just should take care of throttle to not exceed the max current which is 45A cooled...
Thank you for doing this video! I am normally against soldering together a li-ion pack because so many do it so badly but it was a joy to watch you do all the right things to minimize cell damage. A couple of thoughts…
- The Samsung 40T3 cells you’re using go over their 80°C max temperature rating at about 27A (in my testing) to 30A (in Samsung’s preliminary datasheet). In my opinion we can’t say they have a 35A continuous rating as that would get the cells too hot. They can be pulsed at 45A but that’s driving them quite hard.
- Water or an aqueous firefighting solution is actually the best way to fight a li-ion fire. Its mass helps to quickly lower the cell’s temperature below the thermal runaway threshold, stopping the exothermic reactions. You’re then just left with a standard solvent/plastic fire that is easily extinguished, especially if the cell is dropped into water. Putting the cell into sand can help to limit the spread of the flaming ejecta and maybe put out the subsequent fire but won’t stop the reactions driving the thermal runaway.
- If you need to create another pack, try the Molicel P42A. At 30A continuous it delivered 22% more Wh at down to 3.2V than the Samsung 40T3 and can handle the higher current pulses better (less sag, lower temperature). The Molicel P45B, just becoming available this week here in the US, is an even better performer.
Yes, I will be trying the Molicel batteries next. The reason I chose the 40T cells was because the were super-cheap at the time and will do just fine for this "cruising" quad.
@@RCModelReviews ahhh…good point about cost (a priority for many) and the 40T’s being good enough. I often get caught up in the relentless drive for better power handling and capacity that I forget it’s just not needed sometimes.
@@batterymooch Yes, agreed. The Molicel P42As have made their way into plenty of flying machines from my store and they perform very well. I'm hoping the P45B will become the new champ! When working the negative side it's best to go off center, even for spot welds (according to the manufacturers). And Bruce, I see a vintage RG ESC under your meter there. NIce!
Built ni cad and metal hydride packs with a competition electronics turbo 30in 90's. Ever heard of them and can they be used for matching cells that have highest power output? They make gun speed detection devices and quit making turbo 30,and35. Great machine in 90's for making fastest on road cars for me. Foams, pro competition at several tracks in Md. most fun I've had in my life, better than harleys and dirt bikes. Tried to find something for son to do and I liked it better than him. You are the best Mr. Bruce. Wish I had 1%of your knowledge.
Nice video! I mailed you a link to a test-page where you can check the batteries before you buy.
Love your videos keep up the great work I use desolder wick as wire connect batteries together I like it because it is flat they sell different sizes
interesting. what size wick do you recomment for a 21700 6S1P pack?
Just 3 words Bruce, flux, flux, flux. Love your channels.
The problem that most people encounter with lead-free solder is not to do with the solder itself, but their iron.
If your iron is underpowered & you're using lead-free solder (because lead-free solder has a higher melting point), you're gonna have a bad time!
Many lead-free solders don't come with a flux core, or if they do, it's not enough. If you're not using flux with your solder, you're gonna have a bad time!
My soldering iron is a Pine64 Pinecil & I use lead-free solder with that & I have absolutely zero issues with it whatsoever.
Thing I love about my iron is that I can power it straight off of USBC Power Delivery, or a 5s lithium battery, if I so wish; the temperature on it is adjustable; & my iron is deceptively efficient at what it does.
I use that for _all_ of my soldering needs, including assembling high current discharge battery packs (along the lines of 6s 3000 mAh 75C, or 6s 5000 mAh 75C), & it does the job flawlessly.
...& yes, I use lead-free solder. Why? Because maintaining RoHS compliance, & I have had lead poisoning in the past (due to using 60/40 tin/lead solder) & that shit is _not_ fun & I have no intentions of ever getting that shit again.
Sorry Bruce but I have to complain about this one. As you said building your own can be dangerous, however you rushed through this build, and considering a lot of new or inexperienced pilots watch you and may try this themselves, witch could lead to major problems. I know someone who set his house on fire building a pack as he connected the balance leads up wrong and you skipped over this in your video.
So I would say to anyone who is going to try this for the first time Please watch other video's showing how to build a pack, and only use this one as a guard.
Once again sorry Bruce as I'm a BIG fan of your channel and have been for almost 10 years.
Made my Life battery in my first large airplane after watching your original video. that was back in 2011 that I made mine, video may have been older. Man did my life change shortly afterwards. Do I trust an 11 year old pack, that I haven't flown in 5 years? I was going to test that this year, never got the chance. Of course, this is all model airplane talk, not quads which I just didn't groove well with. I guess everything just isn't for everybody. I'll probably make a new pack IF I can get some guaranteed flight times. Till then, I can fly control line in my front yard.
Holy crap, those NZ prices! Just checked what a 6s LiPo costs over here, minimum of 4000mAh, minimum discharge rate of 45C, like the one you posted. I'm starting at 60C, 4000mAh for €54 (Zippy Compact), going up to €128 for a 6000mAh pack rated at 75C (Turnigy Graphene Panther). That's 88-210 NZD.
And those Samsung 21700 40T cells go for about €4.95 in quantities of less than 10, so for a 6-pack, I'd be spending €29.70, or around 49 NZD.
Aussie here, i'm with you on the soder thng it seems more difficult somehow to leave the L off??! May i make a suggestion or two?? if not stop me from typing. The hole in the solder reel looks like it would accept your individual cells giving you a stable holder for soldering and i glue a wooden clothes peg to a piece of wood, that silicon wire conducts heat too quickly for me to hold while soldering, the peg does a great job of saving my fingers. hope i did not offend.
1412, Bruce were you getting that extra solder on the surface or getting it to melt right through the strands? Thanks. Laurie.
Hello Bruce, a bit off topic, would you make exolanation videos on how primary control surfaces work? Most people just explain how you manipulate and move them, but how they acyually work aerodynamicaly speaking?
Is the mah to weight ratio better then a normal lithium polymer?
Get a portable spotwelder. Cheaper than even a half decent soldering iron and loads safer.
is this way can be apply into Aerial / Fabrique Standart Drone? to avoid lipo battrey using mr?
Why you connect the battery in series rather than parallel thanks
What a champ, Parkinsons and still working.
Hi, I'am planning to build a li ion pack for my quad but I have some questions if you can help. As far as I understand, one of your quad motor consumes nearly 8 amps at hover and total 32 amps. At full throttle it goes up 160 amps. But your pack gives 35 amps continues amd 45 amps at burst. If my calculation is correct your quad can hover but hardly fly. Is it more realistic to make a pack as 6s2p configuration with 12 li ion batteries?
Nice video, i try to swap the battery from 3.7V 1000mAh to 3.7V 4200mAh but the drone didnt worked… the blades spins then shut off when try to lift, then it refuse to spin, whats the reason? Do u know if its possible to swap the brushless motor into bigger? Thx for answering
Did you channel AvE at the beginning of this vid?
Enough is never enough
Can you do this with fixed wing aircraft?
Nice AvE intro! 😂
Would you recommend this for a 4s aos cinelog25 I’m building with an o3 au? This is my first build. I like the idea of getting avata like battery life.
Probably a bit heavy for a 2.5" quad. I use a 18650 Li-Ion on my GEPRC cinelog35HD and get about 14 minutes though.
I had a guy try chew me out on here for not using a spot welder on the batteries. You don't need spot welder if your soldering iron and tip are correct. Molicell cells solder brilliantly.
OK, how about 6s2p 18650 or 6s1p 21700, which one you think is the best balance ?
By numbers, a good 21700 6s1p would be 4000mAh and weighs about 414g. Where 18650 6s2p would be if I'm luck 6000mAh.
Also considering the internal resistance which is better with the 21700. I don't know if I could find a good 18650 with a good internal resistance.
6x 21700 cost same as 12x 18650.
Hi Bruce, thanks for sharing! I have a similar charger but in lion mode it only charges up to 4.15V. Are you charging in Lipo mode to get up to 4.2V?
You can charge them in LiPo mode but you shouldn't get to high with the amps. Most chargers do charge LiIon batteries with 0,5-2A at max.
@@ZeroFPVNice to know! Thanks Bro
Why did you jump cut installing the balance lead after stating how important it was to install properly?
I was actually looking forward to knowing how a balance lead works.
Cheers tho the rest the vid was great, I was trying to convince my friend to try this a couple of years back because of how lite they are, just for a long range cruising drone, nothing punchy. Good to see it is viable!
The cells are wired in series starting from negative of the first cell (black) to the positive of the last cell (red). The black (negative) balance wire is soldered to cell 1 negative & goes to the first pin on the balance plug (ALWAYS same side of the JST balance connector no matter how many cells!) then the jumper connecting between cells 1/2 (cell 1 positive/cell 2 negative) goes adjacent to the black wire on the balance JST connector to measure cell 1, cell 2,3,4,5,x next to that until the last balance wire on the last cell in series (red) goes to the opposite side of the balance connector.
How many watts is your iron Bruce?
Isn't soldering the worst for the battery? Why didn't you do spot weld?
Is 2s lion battries compatible to fly 5 inch fpv
Hi don't you need to use bms circuit for lithium ion batteries?
the charger balances the cells using the balance plug
Is there a reason to not contact solder them? The device costs 2 lunches
I'm going to try that in a 5s pack for my 500 helicopter.
Hello sir I just wanted to know about TX . Now a days mulitprotocol TX or so popular. I have using futaba TX I just know which one is better for engine rc plane s futaba jr or Radiomaster please Reply me .thanks
I have 20 40t’s just laying around cause i was gonna make a battery pack for an electric longboard but i got nervous about soldering batteries 😭
Is there any benefit from using nickel strip over wire to join the cells?
Nickel strip is easier to spot weld, and makes a flatter surface with no wire bumps when the pack is finished. If you're not spot welding I can't see any advantage to nickel strip. Most cheap nickel strip is actually nickel plated steel so it's not as good for high current as a nice bit of copper wire. The solder blobs also give better contact for current transfer than spot weld dots. When you're doing large quantities though, spot welding quickly becomes the more preferable option.
That's kinda what I thought. I also think maybe strips need to be stacked or layered to support the current I'd need. Wire seems like the better way to go.
Brilliant ! Well done. BTW, I'm much better at sodering than soldering. Cheers. ;-)
hy i've got some sony murata 3100 mah 35A curent cells to make a 6s2p pack , my concern i about how many nichel strips do i need to get 35A per series pack (35 per pack will lead to 70A discharge total 2p config), i have some 0.2x8 mm pure nichel strip that i've heard and tried that it doesn't like to stack multiple layers, and some nichel plated steel that weld better more buttery. Are 4 layers enough ? should i alter the strips to have steel nichel steel nichel ... also i think it is better to connect the cells in parallel using the strips, at each joint of 2 parallel cells instead of just at the end like if they were 2 separate packs, it should help with balance, but i ask just to be sure. Also even if i stack enough strips on top of each other, all of them will interact with the cell using the tiny spot welds of the first strip that conects all of them to the battery trough it, are they gonna be enough, those spot welds ?
Great video Bruce, nice to see you spreading the knowledge again. And I would agree, if your only making up the occasional packs for yourself, soldering is the way to go. Don't whatever you do go out and buy one of those really cheap spot welders from Ali Express, they can be very inconsistent at best, or just damned right dangerous. I have tried a few of them, the worst by far, and the most dangerous are the ones powered by a lipo battery. They have next to zero over current protection and if any one of the output mosfets goes short circuit, the spot welder will dump the entire output of the lipo into the tips of the welder. And they will give no warning of any such fault, the first you will know of it is when you touch the tips of the welder to your battery, it will then happily blow the end out of your 18650 in a very dramatic way, molten metal flying about, along with your battery letting you know it is not happy with such treatment by instantly catching fire. Unless your willing to spend some decent amount of money on a reputable spot welder, it is much safer to solder.
*I want to put two batteries 18650 3500mAh. how should i connect them, parallel or series. What is better ?*
Thank you
parallel gives double capacity while series gives double voltage
They are only 1.5 times heavier rather than twice as heavy.
You should get some flux paste and it will make soldering 100x easier
No, if you have good quality solder and don't overheat the joint or take too long no additional flux is necessary.
Hey mate how do you overcome low voltage cut off n esc to utilise battery down to 2.8v etc
Disable the ESC LVC.
I see, escs I use have no blheli software 🥲 if you try 4s on that and limit throttle I think you would go passed 20minit easy
cool
HELP😭I Have a directional and multi-directional on a splitter input to 1 tv WHAT AMPLIFIER Auto adjustments i need
👍👍👍👍👍
Can you provide a wiring diagram
Would you make a pack for commission? Also got an idea for nz kiwi flux ,if there's a market.. Xjet flux all has a ring to it!
Nice lookin hat
1500, lol my question answered!
Bruce they are selling Zippy 6S1P 4000mAh 40C LiPo's on Hobby King for NZ$94.
And..... then there's shipping$$$$$ In fact I don't think they even ship lipos to NZ any more :-(
I get 29 mins on a 4s 10,000mah on a 7inch 2806.5 1700kv. You probably better on 4s as well as i bet you can only use about half throttle before its using more than 30-40amp,s. Also i just made a 12s 130c 1100mah hvlipo fully charged at 52.2 volts and use the 12s icharger to charge it
dont do this, never even once use sandpaper on the battey terminals, they will corrode and cause problems, get a spotwelder for this. Bruce, you must read up on this from the DIY Powerwall community... keep it safe!
folding props?
They're the new Dal 7" folds with metal hubs. Hopefully an improvement over the old 7's with plastic hubs (mine have high vibes...)
Li-ions are a requirement for long range or endurance. Bigger quads have no problem with large li-ion packs, my 4S3P 18650 pack of 10000mAh gives me 45 minutes flight time while weighing 600 grams.
i wonder how it will be with tesla cells!!?
Throw the battery in a lipo bag. If flames or sparks happen. Lol
Why do you not spot weld?
Because I don't have a spot-welder but I do have a soldering iron :-)
He explained that in the video.
samsung 30t do deliver better performance, and vdrop was not at significant as 40t. but gently the 40t delivers flighttime.
👌👌👍👍✔✔
Hi, I wanna ask:
I have a Parrot Jumping Night Drone:
Drone: 3.7V 2A Max
Battery Pack: Li-PO 3.7V 550mAh 2Wh 15C Cont Discharge
Battery is dropping. Usually I can play up to 20 mins, now below 5 minutes.
I want to diy using 18650 battery.
I have AWT 3500mAH 3.7V 35A High Drain and MXJO 3500mAH 3.7V 20A (both are authentics). I use for vaping device.
- Can I use my vape battery to drone? I plan to mount only 1 battery, probably using battery slot so I can easily recharge it.
I have Nitecore UM2 USB Charger.
- If can, do I have to tear down the original battery, take the BMS and put into 18650 battery or I can simply soldering cable at drone connector to the battery without BMS?
For safety reason, which is best?
- Also, there are 3 connectors on the drone, I think 1 for battery level, how to soldering it so I can see the battery level on the smartphone.
- I think with 1 single 18650 battery with 3500mAH, I can get very longer play time. I confuse with 2A Max warning on the drone and 30A or 20A on the battery.
Can you help giving me understanding about it? Many thanks.
Thanks to CHAT GPT: Soldering lithium batteries requires caution and care, as lithium batteries can be unstable and potentially dangerous if not handled properly. It is important to follow the manufacturer's instructions and safety guidelines when soldering lithium batteries, as well as any local regulations or laws that may apply. Some general precautions to keep in mind when soldering lithium batteries include:
Wear protective gear, such as gloves, goggles, and a face mask
Make sure the battery is in good condition and not damaged
Use a low-wattage soldering iron, as high heat can damage the battery
Avoid applying heat directly to the battery for extended periods of time
Avoid inhaling any fumes or gases that may be produced during the soldering process
Dispose of the battery properly after use, according to any applicable regulations.
It is generally recommended to seek professional assistance when soldering lithium batteries, as improper handling can be dangerous.
Wouldn't you want a high watt soldering iron at a lower temp? It has been my experience that a low watt soldering iron would dissipate its heat too quickly for this type of work and be unable to create solid connections without prolonged contact. An iron capable of high watt lower temp would allow for less heat loss and require less contact time. I dont have much experience here but not using high watt in this scenario goes against anything I've read.
@@ZippyFPV its about the corrosion protection that gets destroyed with sandpaper. also heat kills the cells.
@@Ge-Fat It has to be sustained heat. A short dab of solder is not going to cause a problem.
@@grantadamson3478 it wont but using sandpaper to remove the protection will cause corrosion on the cells
Low-wattage soldering iron is THE WAY to destroy the cells. You need a powerful iron, 50W, 80W, even 100W is preferable. If the iron cannot make the solder joint in a second or 2, you WILL overheat the cell and damage it. It's quite simple actually.
It's funny because people always argue that you have to Spot Weld Nickel Strips (low conductivity?), and that Soldering is really bad... yet I often hear people with "nickel strip batteries" complain about extremely hot batteries even when trying to fly gentle. Meanwhile with my copper wire (high conductivity!) solder jobbies, I'm blasting at, and above, the Max Output (45A with Molicel P42a cells), and my packs are just sort of warm when landing. Here's a comparison video I did of all my DIY Li-Ion Packs a while ago for example: ua-cam.com/video/rynkx_OYTFI/v-deo.html
Look for some Molicel P28a cells, (2800mAh, 35A Max, 47g); Lower Weight and with really decent Current Rating. I built a 6s2p pack from my Chimera 7 and love it. Anyway, nice video I watched the whole thing even though I build these packs all the time... fun to watch some one else do work I guess..,. haha Cheers!
I'd be willing to bet a coffee their problems with hot packs are related to nickel strips either too thin or just bad quality (nickel clad steel).
@@tonyk.8580 yup, you’re probably right.
Am newbee: what ia a balanced lead?
It's not a "balanced" lead. It's a balance lead/plug/connector. Google or UA-cam will explain in detail if you spell it "balance lead" and search.
Why didn’t you briefly explain how to wire up the “balance wires”? I could have used some balance wire instruction. Not everyone is a clever-trousers like you Sir! 🤓 How to wire your own flight-pack: ua-cam.com/video/wIbHLacozFo/v-deo.html Great video Bruce. 🤓
Skipping the very most important thing is how he connect the balance lead🙄
It is not allowed to solder lipo cylinder batteries!
Oh yes it is... so long as you do it properly.
Oh no! Now the solder police will arrest me for all the fabulous working packs i soldered together.
Just get a spot welding tool from aliexpress...
Wish I could buy these cells but nobody will ship them.