Potential Battery Problem?

[Trendywendy]

Good morning people. A couple of months ago, our 9 month old PV/battery system suddenly stopped charging the Foxess batteries. The state of charge reading on the batteries went down to 0% and was like that for 9 days till the engineer came out. He changed the ‘BMS unit’ and all seems to be working ok but we have since read that if batteries go to 0% they are permanently damaged. Should we insist that the batteries are changed under the warranty or are we over reacting? Thanks in anticipation.

 

[Murdoch]

I think you should address this question to the supplier in writing and see what they say ? If the installer won't give you a straight answer then try the manufacturer.

Don't believe everything you read on the internet

 

[johnb2713]

It depends on the fault, if the BMS was faulty it could be reporting 0% when in fact the batteries were much higher state of charge. It's also possible that the BMS had shut the batteries off showing 0% of the usable range eg a true 10% to 90% on the actual battery. Usually batteries that are abused and damaged swell up, if youre competent or know a competent person to take the covers off and have a look at the cells for signs of swelling.

As Murdoch suggests, write to the supplier, add a caveat that in view of the batteries going down to 0% due to a faulty BMS you expect them to uphold a guarantee of the batteries for 8 years etc (8 years is the norm for EV batteries).