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.