"Ryan Underwood" wrote in message
news
Hi,
I have two hardly-used UPS batteries that were stored two years ago after
the UPS was destroyed in a storm. I've now installed them in a UPS (APC
Smart 700) that had its own batteries succumb to leaking. Unfortunately,
they only have about 5V on each battery (supposed to be 14V), and the UPS
immediately powers off instead of coming on and charging them like usual.
I'm presuming this means that it doesn't like the replacement batteries,
and not that the UPS had some other defect associated with the leaked
batteries.

I was thinking of using an automotive 14V trickle charger to attempt to
charge them to the point where the UPS would hopefully accept them back.
Does anyone know if an automotive trickle current is within the normal
range of charging current for a sealed lead acid battery? Is this a
dangerous thing to attempt? I hate to dump another $75 on batteries when
I hardly got any use out of these.


I'd prefer to see them recharged via via a regulated proper DC power source,
such as a CB 13.8v homebase power unit, rather than a rough DC source like
an automotive charger. Small sealed gel-acid batteries are a little more
delicate than hulking great car batteries. They can be connected directly to
the output of the power source, but I would recommend putting an ammeter
and a 5.6 ohm 10 watt resistor in the line just to monitor what's going on,
and just in case there's any internal shorts on any of the cells. A
voltmeter across the battery terminals wouldn't hurt also. Keeping an eye on
the charge curve, via the meters, will give you a good idea as to the
condition of the batteries.

Arfa