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writes:

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.

Yup, you're right. Thought they were 14V for some reason. Hard to believe the
longevity is really that bad!

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.

Well, it 'chirps' and the light flickers, but then there is no other sign of
life.

Monitor the voltage across the batteries while you plug the UPS in; it should
rise noticeably if the UPS is attempting to charge them.

Interesting. Across one cell, it drops from 5.4V to 2.8V, when initially
plugged in, then after the UPS chirps and dies, it gradually rises again. Not
sure what's going on here.

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 see. Thank you for the thoughtful reply.

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.

I went to batteries.com and saw $40 for the replacement. But it looks like
that is actually both batteries, so it's not as bad as I thought.

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.

Yup. In fact the existing batteries, both the ones that leaked, and the ones
that seem to have failed prematurely, were from different aftermarket battery
retailers on the net. That's what I have been doing is buying batteries and
swapping over the harnesses.

Is it at all possible to buy a long-lasting sealed lead acid battery, or is it
going to be a crapshoot no matter who manufactures it?