Flooded lead acid batteries have boiled dry over 1 month flat. What does that mean?
They are 275 AH deep cycle Crown batteries, they are old but we don't know exactly how old (5-7 yrs), and we have been getting suspicious of them for a while. Fully topped up the water almost exactly one month ago, and all cells were dry today. Recently we have put 180 watts of solar on with an MPPT controller, so they are getting way more ergs than they've had for a while.
We've had the odd dry cell before, and generally they don't hold charge that well.
Could we have set a setting wrong on the controller?
Are they just stuffed?
Is there a risk of them getting too hot and causing damage in the current state?
(I have disconnected the solar array, and topped the water up on all cells)
We also have a 'de-sulphinator' that clips to the +ve and -ve terminals and apparently puts a pulse of electricity through the batteries. I'm not a fan of it but my father reckons its good for the batteries. Could this screw up the MPPT controller causing it to over-charge the batteries?
My main question is - is there any risk of overheating / fire if I keep using these batteries? I've already been sussing new batteries but don't really want to be rushing out to buy new ones just on the New Year holiday period.
As a note, Crown don't do 275 AH now, the closest match is 260 AH, has anyone got any comments on how good Crown deep cycle batteries are? They were supposed to be good, but they are cheaper than a few of the more recognised brands, and the fact these ones are discontinued makes me suspicious.