# TESTING AN AGM BATTERY: Can I use a multimeter?



## Brinnie (Jun 21, 2008)

I have one of those Belkin industrial backup/surge protectors: and i suspect the battery is dead. Any way I can test that with a multimeter?


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## JohnWill (Oct 19, 2002)

You can remove the battery and measure the voltage. Then put a load on it (I like an automotive light like a brake light for a nice load), and see what kind of voltage drop you see. Note that inexpensive UPS units frequently die and take the battery with them, if it's more than about two years old, I'd replace the whole thing.


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## Wino (Dec 1, 2001)

Depending on your location, Interstate Battery has a large selection of UPS sealed GelCell/SLA batteries. They are a little on the high side, but if local, you can save on the freight. There is a company www.Altex.com that I buy from locally and their prices are about 1/2 of Interstate prices. In any case, a battery is less expensive than a new unit. I've got UPS that have been in use well over 8 years with just battery changes. Battery life usually 2-5 years.


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## JohnWill (Oct 19, 2002)

Well, getting 8 years out of a UPS is not the normal. As my vet says for my 18 year old cat. "He's in a very small peer group." Your UPS is also in a very small peer group. Also, if you open that unit up and check the surge suppression, you'll find that it uses MOV's as the active element. By the time 8 years has rolled around, any protection they offer has long since expired, they have a limited lifetime.


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