Parallel different brand lifepo4 batteries together?

I think it has more to do with internal resistance of the batteries, if different they will charge and discharge at different rates. You try it and check each battery with a amp meter and see if they charge and discharge at the same rate.

3 tons wrote:
Though I’m not too sure what Prouse’s background or expertise is (EE, hobbyist-experimenter, YT’er, or what??), but batteries are of a considerable investment - I would assume with variables aplenty (cell types, BMS targets, etc)…Will’s short response seems somewhat dismissive of possible unknown variables..

3 tons

That short answer by Will was a poor choice to post on my part,I guess..

This is the discussion and his video on this subject...

Will's video and discussion

Though I’m not too sure what Prouse’s background or expertise is (EE, hobbyist-experimenter, YT’er, or what??), but batteries are of a considerable investment - I would assume with variables aplenty (cell types, BMS targets, etc)…Will’s short response seems somewhat dismissive of possible unknown variables..

3 tons

Some points on this topic here, scrolling down. Note they say no mixing brands with theirs, and in parallel they derate the charging specs etc. Also with theirs two is the limit in parallel.

They want the batts to be close in voltage when put in parallel, which is not the same as balancing each one first. Other companies have their own guides of course.

https://earthxbatteries.com/lithium-battery-series-parallel-operation/

It's best not do to it, but should work fine *in parallel*.

nOarp and others..Thank you..

An example on why it is confusing to me..

Chins battery wrote on Wills forum...Generally speaking, it is best not to use batteries of different brands together. Because different brands of batteries have different resistances, BMSs, and batteries, etc. If they are used together, they will be incompatible, which will damage the service life of the battery. Therefore, when connecting batteries in series or in parallel, it is recommended that you use batteries of the same brand and preferably purchased within 6 months.

And Will Prowse wrote on his forum concerning mixing brands..Yeah, LiFePO4 in parallel is fine. Just ensure each parallel string has OCPD and that they are top balanced before being connected together, and it should work great.

Thanks

jaycocreek wrote:

n0arp wrote:
If they're actually clones (as in the BMS is the same), then you'll be fine. Different implementations may not play so nicely together and you are gambling on that. If not the same, nothing catastrophic will happen, but you may not be able to utilize the full potential of the bank.

Will Prowse didn't talk about BMS types really in his teardowns and the other guy just said they were average...Not listing the BMS manufacturer....

What could happen if both were differently made?

Depends on how they differ, but nothing substantial and it depends on how they are used, as long as we're talking parallel and not series. The worst case is probably that one BMS disconnects its cells according to some parameter, while the other does not. You are effectively working on one battery until that parameter is cleared. That can cause them to get out of sync with one another, and when the other battery reconnects the cells, the inrush between the two could be enough to cause damage. Unlikely, but again, worst case scenario.

n0arp wrote:
If they're actually clones (as in the BMS is the same), then you'll be fine. Different implementations may not play so nicely together and you are gambling on that. If not the same, nothing catastrophic will happen, but you may not be able to utilize the full potential of the bank.

Will Prowse didn't talk about BMS types really in his teardowns and the other guy just said they were average...Not listing the BMS manufacturer....

What could happen if both were differently made?

If they're actually clones (as in the BMS is the same), then you'll be fine. If different, nothing catastrophic will happen, but you may not be able to utilize the full potential of the bank.

wa8yxm wrote:
How well it will work depends on the product quality. With LiFePO4 the product lines are still new enough that I'd be careful doing it.

I would not be in any hurry to do it myself.. but I suspect it will be ok.

Ya,I'm not really in a hurry to do it either except it is just another unsolved mystery of lifepo4 with battery makers saying only use the same brand batteries in parallel and others saying it is just fine,like Will Prowse and others..Confusing..

The only reason I asked was I have been running two compressor fridges 24/7 with one in freezing mode(8F) and the other refer mode(32F)..One 100ah battery and one 100 watt solar panel keeps up in really good sun but on a rainy day like yesterday,I had three 100 watt panels hooked up and could not keep up therefore draining that 100ah battery faster than I like,it would last maybe three days..Paralleling would increase that..