Does temperature affect battery capacity?

3 comments started 2023-02-27 last 2023-02-27
GivEnergy ProductsBattery
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#1 pacemaker

So I understand the charge and discharge operating temperatures, however I was wondering if lower temperatures affect the overall battery capacity? If so, by how much? How can I do the maths to figure out my actual capacity due to current low temps?

Example, I own the 9.5kWh battery, which is 100% DOD - but is that sticker rating measured at a given temp, like 25C?

#2 Cdent

pacemaker the charge is definitely affected by the temperature, I'm sure there was a topic on here with a graph showing capacity but can't for the life of me find it now 😕

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#3 Anomnomnomaly

Understanding battery capacity is the one thing I've not yet wrapped my head around.

My battery is located in the garage, right next to the garage door, which is almost perfect North facing. So it doesn't heat up at all. The highest temp I've seen on the battery is about 22ºC when discharging at a high rate. Voltages will sit at around 54v, the lowest I've seen as the battery discharges down towards single figure % is about 50.8v

From 4% to 100% only takes about 3kwh to fill a 5.2kwh battery.

I honestly don't understand why it only takes 3kwh to fill it... unless it's not reporting it correctly.

Yesterday and the day before we were using a lot of extra energy for washing machine, tumble dryer and dishwasher... so drawing from the battery as well as solar during the day quite a lot... We actually put more like 4-5kwh into the battery in total and ran the house from the battery until 9-10pm.