From time to time I come across an old computer UPS (uninterruptable power supply) at thrift shops or auctions that no longer worked for the previous owners. In almost every case, the original batteries had expired past their life and just need replacing. It amazes me how many folks will go buy a new UPS and get rid of the old one over something as simple as a battery replacement.
I picked up two considerably large UPS's this week that had just this issue. I paid $10 each for them not even knowing the model numbers. Once I picked them up I did a little research and was a bit shocked at the price of the OEM replacement batteries, almost $70 for each UPS.
So I ended up pulling the batteries out of one of the units, it looked like the one shown above. Upon closer inspection I realized this was just two sealed batteries stuck head to head with stickers holding them in place. I figured I had nothing to lose, so I went ahead and pealed the stickers off. I found what I had suspected and also some battery model numbers/specs to reference.
I took those model numbers and found 4 comparable new batteries for $10 each online.
I swapped the batteries out tonight by simply removing those stickers, unplugging/plugging to the respective connections on the batteries, and taping them back together. Now I've got two refurbished UPS's that I'll be able to use, one on my security system, the other will power the new tankless water heater during power outages (which don't last long around here).
I also find that having a UPS on electronic equipment helps with surge protection and conditions the power to keep sensitive equipment from having a shorter life span.
BTW, UPS's of this size sell for about $200 - $400 new today, I've only got $35 tied up in each of them and should get about 3 to 4 years before needing to replace batteries again.
Last edited by Darren Wright; 09-12-2015 at 05:10 AM.
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