Any charger with decent current limiting will do the job. You want a power supply that will pull the load plus the low battery current, so at least twice the load current probably would be a minimum. What load and how big are your batts? Normally you would want to have a current of at least 10% of the amp hour rating available to charge plus the load current. But if the batts are really really dead, it may be a while before the voltage comes up to an operational level.
From: TJ Trout Sent: Saturday, March 14, 2015 4:53 PM To: [email protected] Subject: [AFMUG] Dc power supply + solar controller for cheap dc ups? What do I need besides a dc power supply to be able to have a dc ups with the ability to charge batteries and have seemless transfer to and from batteries when ac fails as well as limiting on the batteries being charged so the charging doesn't over run the current of the psu once the ac comes back ? Aka poor man's ups? Dell nps700ab poweredge supplies are 12v 700w for like 5 bucks
