Mixing Battery Brands in one Pack?

[EVDragRacer]

You guys have been very helpful over the years and I need your advice again. I am very curious if I can properly build a battery pack with two separate brands of lithium polymer cells. The brands would be split into two separate packs equal amps, and connected in series. So, another words to give more details:

65S of Haiyin 6AH 3.7V cells (10P packs)
to
45S of Brand X 6AH 3.7 cells (parallel amount to match Haiyin amps of 10P)

The reason I ask is because I have been offered sponsorship from another lithium polymer company.

 

[dogman dan]

The only thing I can see is that if one brand is better than the other, then performance would be limited to the lowest performance type.

So for example, if one type is a higer c rate, the pack would still have to stay within the limits of the lower c rate pack.

Same thing with capacity. If you add capacity to one pack to get the avaliable amps to match ( more ah of the lower c rate type) , then capacity is still that of the smaller ah pack.

You knew this already of course.

 

[t3sla]

voltage sag under load could be interesting with with varying impedances, I might be talking total crap but an analogy would be like having different amounts of tread on front and rear tyres.

it should be fine unless someone is playing catchup under load

*wait for lfp to proclaim that the above is a load of horse shit*

:lol:

 

[Ykick]

'don't believe you're really gonna know until you try?

Although not even close to the level you work with I've mixed Zippy/Turnigy RC Lipo a bit and the worst case has been slightly more cell imbalance over time. Of course, that's using relatively similar capacity and C rates.

Another similar situation is when mixing old/new batteries - it's usually nothing dramatic but over time serial bulk charging imbalance seems to increase slightly.

 

[dogman dan]

True, I was not even thinking in terms of them being bulk charged together, just discharged. I assumed seperate charging if they are very different, particularly if different in size.