Ryan Underwood wrote:
Unfortunately, they only have about 5V on each battery (supposed to be
14V),

Actually, something in the region of 12.6 V, no load. If they sat for
two years and only have 5 V no load, the probability is high that they
are junk.

and the UPS immediately powers off instead of coming on and charging
them like usual.

I may be misunderstanding you, but in my experience with a few different
APC UPSes, the UPS doesn't have to be turned on (delivering power to the
outlets) to charge. As soon as you plug the cord into the wall, it
should start charging. Monitor the voltage across the batteries while
you plug the UPS in; it should rise noticeably if the UPS is attempting
to charge them.

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?

This depends entirely on the charger. What is its rating, in amps?
What is the amp-hour rating of the batteries? This is usually printed
on the battery. Panasonic even helpfully prints basic charging
information on their sealed lead-acid batteries. You might look for a
data sheet on the batteries you have. If they are no-names, you can
still get an idea: these batteries come in several standard-ish sizes,
so if you can find a battery similar in physical size and electrical
capacity to the one you have, you can use the data sheet for that
battery to get some idea of the charging parameters.

If you have no other information, you want to set it up so that the
battery will take 8 hours or more to fully charge. For example, I have
a 600 VA UPS that uses 2 12 V 7 Ah batteries. Using a 6 amp charger
would probably be too much, because that would recharge the batteries in
a little over an hour. I might chance using a 1 amp charger (7 hours to
charge), but it would be better to use one smaller than that.

I hate to dump another $75 on batteries when I hardly got any use out
of these.

Assuming your 700 VA UPS uses something like the 2 12 V 7 Ah batteries
my 600 VA UPS uses, $75 is way too much. I can replace these batteries
for $15 or so each. As another example, I have a rack-mount UPS that
takes APC's RBC18 "battery cartridge". If I buy it from APC, I pay
about $70. If I buy the individual batteries from Digi-Key or Mouser
and swap the wiring harness over myself, I pay about $25. Now, if you're
using your UPS to support the payroll server at your office, or an oxygen
machine at home, you might be interested in paying the extra $50 to
secure the right to sue APC if the batteries crap out. But for almost
everything else, DIY is the way to go.

Matt Roberds