Correct charging settings for lead acid batteries

[Peet Welthagen]

Good day, what will be the ideal charging settings for 12 x 200ah lead acid batteries. Connected  4x in series and 3 banks in parallel. I have got 2x Axpert 5000 kva inverters in parallel.

Regards

[WJP]

Can't comment on the voltages but 20 amps per bank, 60amp charge rate in total.

[Coulomb]

17 hours ago, WJP said:

20 amps per bank, 60amp charge rate in total.

That's for a charge rate of 0.1C, which I think is very cautious. Most lead acid batteries can take 0.15C, which would mean 200 x 0.15 = 30 A per paralleled string of battery modules, or 90 A total.

The settings of each inverter-charger add, so you could achieve this by setting one to 50 A maximum total charge current, and the other 40 A. Obviously, if one has more or better solar panels connected, make that the one with the 50 A limit.

The recommended charge current and voltage should be available in a specification sheet available from the manufacturer (on paper, or more commonly these days on a web page). You didn't say whether the battery modules are sealed, flooded, or AGM. If you leave the battery type setting at AGM, this will charge each 12 V module to 14.1 V, and float at 13.5 V. Those settings are pretty safe for most sealed battery modules. Ironically, actual AGM battery modules usually require higher voltages than that.

[Peet Welthagen]

Thank you