Alfalfameister

Using a power supply to give out 13.8V (just for a continuous float charge), can you hook up SLA batteries in parallel so you can keep them charging that way?

What I basically want is a high-capacity UPS. One way for getting the high capacity, I thought, was to hook up the batteries in parralel, thereby increasing the amp-hours total of the battery.

Can this be done?

The scheme, basically, is this:

Power Supply -> Battery -> Inverter -> [appliances]

[link]http://www.dansdata.com/diyups.htm[/link]

If you disregard the computer, this is what it looks like:



The question is, can you hook up 2 (or more) SLA in parallel... Would there be an imbalance in the charging (like... what if one battery was already charged -- although not topped off since it is on a float charge -- ...if one battery was already charged, is there a danger in overcharging it since the other one is still not charged?)

Er... is this quesion confusingly worded?

richrd

Setup it’s all in the setup. Lead Acid all the easiest to parallel and they float well at and around 13.4V. But for best setup all batteries the same exact age, model etc. If not they may not share well together so one may over draw current start to over heat and then second battery may draw some current. They self balance some what but it’s not the correct way to parallel. Sharing works both ways charge and discharge, but if charge current limit is set to the weakest battery then ok on that side just slow. On discharge the same if current does not exceed the weakest battery then no problems the weak one drains down then next battery starts to deliver until all dead @ 12 V stop.
Hope this helps some…Rich

Alfalfameister

I could always count on you (richrd) to come up with a reply. I was making an internal bet who would provide help first, you or JNorton. Haha!

Thanks a lot! I will just charge at 13.4V... and then maybe once a month, top it off properly (and separately) with my Swallow charger...

Thanks agian!

--Alf

richrd

Ya always good to help.
BTW try to get the batteries same voltage before connecting unless you are looking fouth of july sparks.

Hey where is john
Rich