"Inverter" jk bms low T threshold

[hogback]

Does anyone know how the low T setting is supposed to function? I set mine to 2degC. I have 8 bms in parallel. If the shed gets near this temp, allowing for error in the bms sensors and transducers, I was wondering if some of them were to stop charging (but allow discharge?) that by the time the hysteresis allowed the 'off' bms to charge, that these batteries would be at enough of a soc difference that a large current would flow when they reconnected, possibly flipping my dc breakers or blowing the fuses, further exacerbating the problem. Thoughts? Thanks!

 

[kommando]

Below the Charge UTP no charging is allowed until the T goes above the Charge UTPR. As discharging is still allowed then the charge % will still drop if loads are applied but where is the extra flow coming from when charging is re enabled to trip a breaker? None that I can think of.

 

[hogback]

If you're only charging some of the batteries, won't the V drift a bit, then allowing large current to flow once reconnected?

 

[kommando]

I have three JK PB BMS and the temps given are within 0.2C, not enough to allow the V to go that badly different. Use the dry contacts to turn on heaters so they stay above 2C.

 

[hogback]

I was planning on a space heater set to 3degC as an interim solution....

 

[LydMekk]

If it were me I would up the temp a bit to stay f.ex. at 8c, atleast not under 5c.

 

[Hedges]

There is a temperature vs. current curve.
How low you set temperature limit should depend on how high a charge current is available.

Post in thread 'Why you cannot charge LiFePO4 below 0 degrees Celsius'

Jan 26, 2021

Since this topic is gaining interest again, here are a few more tables showing the same trend as the Ganfeng Datasheet for other manufacturers

CALB SE series datasheet is the clearest but least detailed (and doesn't acknowledge SOC):



ETC 228 is quite similar in presentation to Ganfeng, but min of 0*C and SOC doesn't appear too important:


Here is the Ganfeng table again for comparison (the only one shows that shows...

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