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hey I have a request! Can you guys post some pics of what your main (+) and (-) terminals on your batteries with the main lead welds look like? I need an idea of how I should go about soldering those and can’t find any good pics of that anywhere. Thanks!
The charge port/wiring has to support the combined amperage but that is also an option
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just solder quickly between the cells at 2 places like 5mm long each connection
sorry dont have any pics
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is it bad if my weld overlaps any of the spot welds between the nickel and the cells?
like welding two times on the same place?
i dont see an issue there, but if your stacking nickel on nickel ideal is that you weld on a smooth surface if you cant just use extra pressure
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yeah sorry it’s hard for me to articulate exactly, I mean like is it safe to weld the main terminal leads directly on top of the spot welds (I know they should be done in between the cells, but is it ok if the main terminal lead weld spills over onto the spot welds at all?)
It is 10P atm but will be 6P which is 15A Max charging at 1C. At the moment on 6S10P I can charge at 25A but charge at 15A for the reasons @ZachTetra metions.
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Ah, I totally missed that. My bad.
Still, 6a for a 6p pack is pretty weak. I think you could go 12a for the 6p and still be in comfortable territory. I’m going to be charging my 10s3p 30t pack at 6a (5.71a), if that helps you make a decision
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Yeah I wasn’t going to go 6A, was going to try go around the 12A mark but can’t find any power supply capable of that at 42V.
@Harrisonwms1 I’ll do some research into that, Cheers.
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Hey guys, would a single strip of 0.2mm x 10mm wide nickel strip be alright for a series connection? This will be a 10s3p pack.
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by weld you mean solder?
thats not an issue at all 
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If you can do the serial connections by wire
Could i do away with 14 AWG? My width space is limited that’s why i thought of connecting via nickel strip.
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Yea it will do
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Nickel alone, no. Don’t do that, nickel is a poor conductor, and those strips are very thin. Either copper wire, or copper braid is what you want. If you can’t fit a single piece of 10-12awg, then two or three pieces of smaller wire in parallel will also work. Look up the cross sectional area of different wire sizes, and you can see that 12AWG has about 3.3mm2 of area, where 14 has about 2mm2. So two pieces of 14AWG will be even better than a single piece of 12.
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Hey battery gurus, I am trying to decide between Samsung 30q cells and LG MJ1 cells. I am interested in the MJ1 because people say it has a higher cycle life than 30Q but is that really true under our use case?
I know 30q is considered very durable compared to others but that is at 15amps. I wont be going that hard on them.
The easiest to find info shows 30q at 300 cycles and MJ1 at 400 cycles.
Although when looking at the data sheets of the two, the cycle life test have been performed at different amp levels. The MJ1 was tested at a lower amp level making it naturally have a better cycle life.
Can anyone find cycle life test for both done to the same standard?
LG MJ1 - 400 cycles, charge 1.5A, discharge 4A (80%)
Sam 30Q – 200 cycles, charge 4A, discharge 15A (80%)
Seems like the cycle life for both is close to 300 if the test was the same around 10A?
My planed use is for a commuter, each cell will be discharged regularly at 6-7a and occasional peaks of up to 10a. Charged @0.5c. Low voltage cutoff 3.3v
Although I did find this comparison from NASA although the discharge rate appears to be only 0.58A?
This is 30Q from Samsung’s data sheet, discharge at 15A and strangely charge at 4A.
Although MJ1 at 80% capacity has more left than 30Q at 80% Still I have not seen MJ1 life cycle tested at a decently high rate of draw to draw a conclusion for my usage.
Might want to have a look at Sony vtc6 as well.
They seem to have a better cycle life than 30q, do perform similar and depending from where you order are priced similar as well.
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I haven’t used the MJ1, but 30q seems overkill for your use case and the MJ1 also has a higher capacity…
I’d be going MJ1 if I were you.
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