Battery too cold to charge

I have had a problem with my battery going below 0C wth no charge and then not being able to charge itself.
Do I need to insulate it? Will it get too hot in summer if I do this?

Is this a new install ?

I take it you have it outside ? if it's outside it's been said before that at hut/mini house around the battery is a must as not only does it help keep the battery dry but a gives a few % warmer

Not sure if you need to insulate the battery, seems over kill, but mines inside my home

L134964 insulation is a good idea in Winter but remove it in Summer.

If you charge it overnight, it will always be warm. Insulation wont keep it warm without being used as well

Both of mine (in the loft) went into a deep sleep mode during the Dec cold snap, GE revived one remotely when I turned both on using the push button switches on them. The other one they're are sending an Engineer out to hopefully sort. They said that putting insulation on is fine, so I put some 200mm rock wool on when it got cold again in Jan, it got up to 30 degrees C on the discharge and went as low as 11 degrees C when idle. Ever since the outside temp has been above 0 I've taken the insulation off again.

My 8.2kw battery is outside. I have knocked together a wooden frame that covers all the equipment (battery, AC3.0 and Solis inverter). It has roofing felt on the top to stop the worst of the rain and is covered with 3 layers of greenhouse shading. This kept it cool enough last summer. I got a sheet of 5cm polystyrene and glued an tape together a 3 sided box that slides over the battery, but can be easily removed in the summer. I also do a long slow charge of the battery overnight on sub-zero nights (about 1000-1200w), as when the battery is charging or discharging it generates heat and this together with the insulating cover keeps it toasty and within operating temperature.

My battery is on the inside of the outside wall of the garage, so its not going to get the worst of the outside temperatures but it won’t be all that warm either.
Looking just now my outside thermometer says -1 degrees and the battery temperature is reading +8 so its not too bad.
But this gets me thinking, whether I should be insulating the battery in the garage at all (I don’t do any overnight charging of it so it won’t warm itself). What is the recommended operating temperature range for the battery?

My battery is in my garage and was going down to 2 deg C. I now have some insulating foil and a blanket over it and now it doesn't go below 5 deg C even on the coldest of nights. I have also adjusted the charge rate so that the charge is spread out over the whole charge period and this has also helped with keeping the battery warm.

Hi Geoffrey, I am new to solar so no authority but I have seen 25 deg C suggested as ideal. If your system was inside the house like many it would naturally be around 19-23 deg C as that suits us humans. I think many people make insulated boxes to keep out the worst of the cold. You can monitor battery temps on the dashboard and, in my opinion, should if you decide to insulate. As the summer comes you would need to ensure it's not becoming too hot.

geoffreycoan My battery is in a detached garage and we are out in the fields so windchill can be hard. Nevertheless, even in the cold snap we had a few weeks ago and air temps droppped to -10 outside the battery remained within operating range for both charge and discharge. I use Home Assistant and givTCP and one of my automations monitors the battery temperature to give me a warning if it gets below 3C but it's not been triggered yet. The automation also forces a discharge at low power to maintain the temperature above 0C and so keep it's ability to charge during our off peak period. As I said, apart from testing, it's not been triggered.

And to think - just two or three short months before threads appear about keeping inverters cooler with extra fans, lol.

You gotta love our weather.

Very late to reply - sorry everyone as your commnets were very helpful.
We know have an insulated box for winter which comes off in summer and I stop the battery running down too low over night in the really cold weather. It would be helpful to get this advise when the installation is carried out but E.On were a nightmare anyway.

The inverter and battery have a rain cover and are in a very sheltered position so don't overheat - at least not so far.

cluelesscris Amusing to find posts I made over a year ago, how things have changed. I'm now on Agile and using Predbat with Home Assistant so am charging every night.

Looking at my history, the lowest the battery has ever got is 8.8 degrees and the highest 49.7. So I don't think there's cause for concern with this range but I'll create a HA monitor to alert me if the battery does drop below 3 degrees so I can go out and cuddle it warm.