Our battery and inverter are outside, and during the recent cold weather our battery stopped charging and dropped to 0% for 3 days. The installer is saying that the cold weather did that, but from what I have read the battery should operate between -20 and +50 degrees. The battery temp never dropped below -5 where we live. We couldn’t force charge from the grid. Has the same happened to anyone else?
Jumbo99 This has been noted by a few people. I think and others may confirm that the new firmware will help.
The battery can discharge below zero degrees, but needs to be above zero to charge, otherwise it can damage the internal battery chemistry. The system will prevent charging at this temperature for this reason. It is possible to warm the battery up by discharging it (putting the kettle on for example), or by wrapping it in a blanket.
Jumbo99 You should find that the operating range for the batteries is not that straighforward. Generally, the type batteries will discharge quite happily a very low temeratures but charging them below freezing is potentially damaging. The BMS will make sure all operations remain within spec.
My battery (9.5) will discharge between -10 and 50 but only charge between 0 and 50.
Charged batteries are safe to leave unused as low as -30.
I employed a regime in the cold spell where I made sure the battery never got to the minimum level so it was always either charging or discharging (means managing the charging and discharging rates a bit). This meant it was always generating some heat internally and so never dropped below 0 or 1 degree even though the ambient temperature was -5 or -6.
Once it started charging the temperature rose up quite a bit so actually I probably didn't need to worry about the charge rate, but I did try to make sure it spread the charging over the cheap period as much as possible so it wasn't idle for too long.
Does add to the impression that these things aren't plug and play yet. You do need to actively manage them.
andyparrott I think indoors they are pretty much fit and forget if you want to - but outside is a different matter it would seem.
They definitely don’t tell you that when planning
anglefire Maybe, although I'd be a bit wary of the heat during the summer. Just imagine having a battery and inverter chucking out heat into your house when its 40 degrees outside.
Best place is in a garage or similar.
andyparrott believe it it not the installer wanted to put it in the loft….no chance! Not with last summer and generally the extremes
andyparrott Ah, when I said indoors, I was thinking more like the garage - which is where my system is located - the temperature in the garage did hit 36'C in July. (Yes I do monitor it - as I do the loft) Interestingly, the loft got to 38'C so not significantly different.
They do get installed under the stairs, but I would worry about ventilation.
I certainly wouldn't have an issue with installing a system in the loft - except the physical install of it and its ongoing maintenance. So garage or outhouse to me seems the best option.
Oh and the lowest the loft and garage has seen so far this year is 3'C - lowest outside -5'C
Jumbo99 You can try a long lowish charge overnight. Go to the battery settings on the inverter tab and reduce the charge rate so that the charge is spread out over the off peak period (if you have ECO7). I've found about 1000-1200 seems to work. I once dropped it down to about 850 and that night it stopped charging so it obviously wasn't enough to keep it warm. I also wrapped the battery in loft insulation - the sort that comes in a plastic/aluminium bag - to try to keep it warm.