Lithium charging at low temp !!

[Bessy765]

Hi all, I have 2 x 100 ampTransporter energy batteries, on the spec sheet it says they will discharge between -20 to 71C And charging between -4 and 57C. As our van is kept in our garage it gets no benefit from our solar panels. With the monitoring and parasitic load it consumes around 9 to 12 w Per hour. Given last nights low temp forecast -5 c I turned on the EHU. Van temp was 5 c battery temp 3 c. Set the heating to 10 c. Batteries are one under each front seat and close to a front blown air outlet. I noticed the slow rate of charge by 21:30 the battery temp was 6 c and the van 10 C. first three pics it was on float last one absorption.

It was only after another hour or so it began to increase the charge rate. Mains input was set at 10 amps (Victron 12/2000/80) inverter charger. And heater was set at 1 kw.

 

[Googlebot]

Mine haven’t charged for a week with the solar as the temp has been too low.

The BMS also kicks in and fools the shunt so will have to fully charge them when it warms up.

 

[Bessy765]

Thank you for your reply, I just wondered why if the spec says they will take a charge from -4 c upwards, why would they not take a charge until I had the batt temp 7 c. No biggie but as my van is inside I have to periodically top the batteries up to recover the drain. I can get over it by putting the heating on but dont want to cause condensation with changing temperature. Because of the size of the cabling and location it is not practical to fit an isolation switch.

 

[bigtwin]

I just wondered why if the spec says they will take a charge from -4 c upwards, why would they not take a charge until I had the batt temp 7 c

Hysteresis.

There has to be a delta between isolation and reconnection, though yours does look a rather large delta.

Does your BMS/App show these settings?

Ian

 

[Bessy765]

Never found the bms app on the app i have it just shows what is happening state of charge amps in or out etc

^{_{Subscribers  do not see these advertisements}}