This is why
Cos people still think that a bigger dick is better
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Alright look here. We’re gonna disagree on a few things but mines definitely smaller
Lads… we are talking about batteries here… NOT dicks.
It’s controversial because there is too many variables. Cell differences, P group differences, cell life, parallel connection length, dual BMS or single, etc etc etc. It’s not a simple answer of yes or no and more based on per-application basis. Every electric car uses parallel battery packs, some people are more careful and say match cells, some people just let the cells be and have them a little extra wear and tear for convenience sake.
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The Irany is all my battery’s are to big and it’s not the capacity that determines the size it’s the internal resistance to produce the discharge I want. I’d much prefer slapping on a extra battry for range when I want it. 30q minimum 4p for me trying a VTC5a as a 3p but it dose have more voltsag than I like but it’s only for a little comuter spud
Put simply, cells of the same type (i.e. Samsung 30Q can be built in parallel and they will experience the same loads and voltages.
Cells of different types (30Q, 25R) and the same chemistry will experience the same voltages, however the weaker cells will probably degrade faster and their capacity is probably less… We can all agree mixing cell types will degrade the weaker ones faster.
In other words as long as your cells are the same type they are fine in parallel. I feel like certain people in this topic have a misunderstanding of parallel lmao
Saying that the same cell type and chemistry varies between batches is ridiculous and nitpicky. You could buy 300 cells one time and place another order for 50 more and they might be slightly different but it would be silly to not build a P pack out of them.
If you ran on the 300 for a bit first then that is a different story because now you have run charge cycles on the intial 300, POSSIBLY causing the new 50 to work harder to make up for the sLigHtLy degraded 300. However, they will still have the same voltages because they are in parallel, so maybe they will heat up more but you probably will never know that they work harder.
Yes
Not on the loopkey, on the charge port or in parallel
Also both batteries need to be the same charge level when connected together. Easiest to charge them both with the same charger first
Adding 2s on a loopkey makes 12s6p out of 10s6p? How does that work?
The short answer is that it doesn’t work, except maybe in some tightly controlled non-real-world laboratory conditions.
TL;DR: do not try it unless you’re an electrical engineer. Only add P groups together
I would say everyone is right in this thread. let’s see those two cases:
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drawing only 10A from pack capable of 100A cont. discharge and we add another pack (different cells than first pack, 50A cont. discharge) - now we have 2 packs capable of 150A cont. discharge together. But we discharge only 10A, so it is definitively better to divide that current on 2 packs than on only one. less stress on each cell.
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drawing 90A from pack capable of 100A cont. discharge and we add another pack (different cells than first pack, 50A cont. discharge) - but we increase draw from 90A to 135A. now we discharge at 135A out of possible 150A. in this case, cell type, Internal resistance, wire length and thickness will have much bigger role and one pack with degrade faster than other.
in esk8 we see case 1) much often, so mixing different (decent) packs/cells is almost always good. more cells in parallel, better!
As for connecting additional 2s to make 12s, I don’t see why not? if you disconnect it and charge it separately after each ride so each cell will be same voltage as cells in 10s pack, should be no problem. also they has to be same cells, probably used around same amount. But you could discharge them to only 3.3-3.4V per cell so you will stay on safer side and won’t risk destroying anything. also very important, if you have 10s4p 30Q, you can add only 2s4p 30Q, nothing else. or you can, if you will take extra care and know what you are doing.
I don’t want to go 12s as top speed isn’t really important to me. Was just curious of how it works to be honest. All I want to do is connect a top mounted 10s2p 30Q cells with my main bottom mounted 10s4p 30Q cells batt. I prefer to double check my thinking before proceeding to execute my sometimes rather stupid ideas. Thanks to all of you! A lot of useful information.
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Really basic drawing… Just double checking everything I do. This will make a 10s4p and a 10s2p a 10s6p correct?
Yup basically that.
If I was attempting to do the same and parallel a 10s3p 30q with identical battery from same maker would I have to do anything more than using a parallel cable? Also can I charge them together or do I always have to disconnect discharge?