Question from Spain (And a Hello)

[Bubble]

New to the forum and new to Solar.
We live in Spain so have more sun than you guys in the UK!
Our installation is 48v, 12 x 450w panels - 5 each side of a N-S ridge line roof, 480Ah of lead acid batteries, and 5.6Kw inverter.
All very impressive!
We were using about 12Kw per day, then back in January were using an extra 6Kw for heating in the evening. (Heating by reverse cycle air con units).
I'm interested in battery life against what battery voltage we set go back to the grid.
a higher voltage means the batteries last longer but we pay more for the mains electricity.
What minimum voltage to people set for the batteries to recharge (just set ours to 47v) and/or what battery capacity do you let the batteries go down to?
Thanks

 

[Geoff1946]

I suggest you need the battery manufacturer's recommendation for that. I would expect it to vary depending on exact battery type.

 

[binky]

assuming you have lead acid leisure batteries, I think they can be regularly discharged to about 90%. Charge cycles is around 3000. Voltage affects cable sizes more than anything else, higher voltage means lower ampage and therefore smaller cables. Keeping batteries away from extremes of discharge also affects life, but dont ask me how much, it's not something I've worked with much.