Maintenance charging of lead-acid battery bank (8 @ 6v)

[Elquery]

TL;DR Summary

What equipment and considerations do I need for maintenance charging a battery bank used as solar storage. 8, 6v deep cycle lead-acid batteries.

Hi.

Could anyone guide me as to what equipment and considerations I need for maintenance charging a battery bank used as solar storage. The bank consists of 8, 6v deep cycle lead-acid batteries (Rolls batteries: S6- GC2-HC)

The solar system is for a seasonal application and the shed they typically live in is unheated and the solar supply becomes unreliable.
The plan is to bring them indoors (ventilation concerns?) and use some sort of 'trickle' or 'float' charger.

Is there a way to do it for the entire bank. Are there balancing concerns?
The bank is utilized as two parallel strands (so 4 6v batteries in series: parallel with the other 4 in series)

Thanks for any insights.

 

[anorlunda]

The main thing is to get a good 3-stage smart charge controller. Sometimes those are combined with MPPT solar panel controllers.

Lead acid batteries are often connected in parallel and charged as a bank. They should be the same brand and the same age, but perfect matching is not required.

You may also look at an automatic watering system. Even one cell running low on water ruins everything.

batteryuniversity.com is a good source for battery advice for all types of batteries.

 

[Elquery]

Thanks anorlunda.

I'm looking into it more.
Am I understanding correctly that if I wanted to charge all 8 6V batteries on the same smart charger, I could use one 24V charger by running 2 parallel strings of 4 batteries in series. Are there concerns with the AH ratings of charger/batteries or is voltage all that really matters in this case?

For what it's worth, the batteries, when in use as solar storage, are hooked up exactly as that (2 parallel strings of 4 batteries in series). I was thinking retaining this set-up for the maintenance charge would make sense.

 

[anorlunda]

Chargers are rated by amps, not amp hours.

If you put an undersized charger on, it will just take longer to charge, but not damage anything.

3-stage smart controllers are the important distinction. Be sure to set the controller to match your lead acid battery type --- flooded/gel cell/AGM.

Did you check batteryuniversity.com? They are the authorative source.