Balance two lifepo4 100Ah batteries from different manufacturers
- Thread starter nitot
- Start date
Without experient it will be hard to stay...if you have stubborn cells eventually it will destroy good cell also because of non stop balancing. If you have deltaV high like 0.2 V or more you will need balancer 2A minimum and be very careful when charging. If charging current is higher than what balancer can work with it will not keep up with charging current.
If the batteries will be put in parallel you don't need any sort of device to keep them in balance. Fully charge each battery before putting them in parallel. Then wire them in parallel correctly and they should be just fine.
Will has a video showing different brand batteries in parallel:
Will has a video showing different brand batteries in parallel:
If run as parallel battery banks you will be locked on Ah of pack that has less Ah.
If you running in Series you will have set bms to stay on flat curve especially on low V of lifepo4 chemistry otherwise you will face problems with balancing overtime.
But 3 Ah difference is not the problem if they accept charge and discharge close to each other.
Interesting! I rely only on the BMS that is built into each battery. Do you have a BMS that controls multiple assembled batteries?
Good info, thanks!
This isn't true. You can parallel a 50Ah battery and a 100Ah battery, for example. You will have a total capacity of 150Ah. It will work just fine. The 100Ah battery will provide 2/3 of the discharge current and take 2/3 of the charge current. The 50Ah battery will take and provide the other 1/3. Both will be at the same voltage.
The above assumes both batteries are the same chemistry.
Thanks so much!
In theory. But in reality here is what will happen pack that has higher Ah ratings will naturally provide more current in parallel than pack with 50 Ah. As SOC continues to drop two packs will start drifting in the Voltage vs SOC ( we know that this chemistry has quite flat curve).And one that is dominating on Ah will make other pack in parallel that is almost empty at the voltage as pack that still has good SOC. And by doing it this way pack with less Ah will always have to do catching up and eventually it will trip bms. Try to do experiment on the benchtop . And once you stop discharging if you have clamp A meter you will experience pack with higher Ah ratings trying to charge one that is near empty. There is way around it by setting BMS to stay on flat curve on low SOC , there other ways to make safe setup when dealing with different Ah ratings in parallel. I'm not judging but providing true experiments i have done so far .
Got it, I'm wiring in parallel, so I won't worry about a balancing device
Only downside with any battery banks in parallel that run individual BMS for each pack in parallel is if one of them trip or goes to protection mode .You will have to make sure that voltage between one that tripped and rest of the pack in parallel are the same. Bring all packs to the same voltage before doing parallel connection.
BMS that can talk to each other are nice option if available.
Similar threads
