How hot do you let a downtube battery get? Is 45-50°C too hot for safety?

harrisonh

100 mW
Joined
Mar 27, 2016
Messages
37
Location
Michigan
I have a 10s7p Panasona GA battery pack from Ebikes.ca
It was stated as 40A continuous/max BMS.
The BMS allows for up to 150A though... (I change the bms shunt to test this, did not actually run 150A).

During my 30 minute commute, I use it at 45A for about 1/5 of the time to keep up with traffic. And less otherwise (maybe 30-40A). After my 30 minute commute, I plugged it into my Cycle Satiator just to check the temperature (not to charge). I use about 9-12Ah out of the rated 23Ah and charge at work.

Is this okay? I don't mind decreasing it's battery cycle life too much since I would like a more powerful battery upgrade as soon as this dies, and I only commute 2 days a week... Just worried it might melt or cause a fire.

I read Tesla purposefully heats up the battery to 50°C for ludicrous mode. And, GA cells' "max" continuous current is 10A each, which would be 70A for a 7p pack.

I soldered thicker 12AWG wires between the BMS and downtube connector, but still the ~14/16AWG wires at the actual connector.
Also decreased the shunt resistor a tiny bit to keep the heat generated there about the same(about 4W of power), since it doesn't actually help with current limit anyways...(Maybe I should just solder I wire there to bypass the shunt to decrease the heat?)
 
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