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Why is my battery charging?

Posted: Wed Nov 20, 2024 8:55 pm
by MartynWheeler
Just had a fox system installed. We have 6 panels and a battery.

I have set it up in the app to charge overnight when we have a cheaper rate. This was working OK but I just noticed this evening it is now charging outside of the set time. I have attached a screenshot.

Any idea why it might be doing this? And more importantly how I can stop it?



Thank you
Martyn

Re: Why is my battery charging?

Posted: Wed Nov 20, 2024 9:49 pm
by RobinPattinson
I have the same issue! Only noticed this happening this evening

Re: Why is my battery charging?

Posted: Thu Nov 21, 2024 8:31 am
by Dave Foster
The settings look ok, and you soc is above minsoc (if it were equal to it you will see a small bump charge every hour or two).

But your battery temperature is 3.6C - where are they located, in an enclosure, any insulation?.

When the battery drops below 10C it’s operation will start ti be limited and should it get to 0C the battery will no longer allow charge until the temperature recovers (it will discharge all the way to 10C but cannot be charged) - the BMS will try occasional small low power maintenance charges to keep the batteries warm which I suspect is what is happening here.,

Re: Why is my battery charging?

Posted: Thu Nov 21, 2024 9:41 am
by MartynWheeler
It is on the back of the house as per the installation. It's pretty cold at the moment. How would you insulate it outside?

Thank you
Martyn

Re: Why is my battery charging?

Posted: Thu Nov 21, 2024 11:28 am
by RobinPattinson
Hi Martyn, mine done exactly the same last evening. Stopped charging around 1130pm. Looking at the graphs, it didn’t look like an occasional low power charge due to temperature but I may be wrong. If it was this then not sure why it would have suddenly stopped?
Here is the charging graph….

Re: Why is my battery charging?

Posted: Fri Nov 22, 2024 4:49 pm
by reef
RobinPattinson wrote: Thu Nov 21, 2024 11:28 am Hi Martyn, mine done exactly the same last evening. Stopped charging around 1130pm. Looking at the graphs, it didn’t look like an occasional low power charge due to temperature but I may be wrong. If it was this then not sure why it would have suddenly stopped?
Here is the charging graph….
It'll definitely be due to the cold. The temperature at the top of your image looks like it's showing 2.2C. It appears the threshold for this behaviour is approx. 4C. Below 0C it won't charge, so it's a last grasp effort by the BMS to maintain the temperature before it gets too cold and can no longer charge.

Re: Why is my battery charging?

Posted: Fri Nov 22, 2024 5:39 pm
by MartynWheeler
Thanks for the response.

Do you have suggestions on how I can insulate the battery from the cold?

Re: Why is my battery charging?

Posted: Fri Nov 22, 2024 8:41 pm
by Dave Foster
MartynWheeler wrote: Fri Nov 22, 2024 5:39 pm Thanks for the response.

Do you have suggestions on how I can insulate the battery from the cold?
Have a look at this post, a good example there https://foxesscommunity.com/viewtopic.php?p=5476#p5476