UPS Hacking in Hurricane Season?

kengreenebaum asks: "Perhaps not the most exciting of topic; however it is storm season and I have a couple of UPS's that need new batteries. What is the best source for high quality, long lived replacement batteries for these devices? I assume it takes a special chemistry to survive continuous trickle charging and an occasional deep cycle. Has anybody tried connecting larger capacity batteries external to the UPS enclosure to attempt longer run times? (Obviously the load capacity is based on the inverter itself and can't easily be modified) Also what software do you use for monitoring and automatic shutdown on Linux? I have collected quite a few APC and Belkin UPS's 700VA or smaller as they go on rebate/sale."

Comments

UPS' Contain Standard Gel / Sealed Batteries

[nuxx]

Just FYI, if you have a UPS with replacable batteries (not the crap throw-away Energizer or whatever brand ones) it's very likely that the battery inside is a gel-type sealed lead acid battery. Just take the battery out and look at the markings on them. Odds are good that you'll be able to find a replacement either on eBay or any of the cheap battery suppliers online.

Myself and a number of friends of mine have acquired SmartUPS' (typically >1400) for free, simply because they are 'broken', and a battery replacement costing around US$50 or so makes them like new. Oh, and a good SmartUPS is really, really nice compared to a standard passive device.

Re:UPS' Contain Standard Gel / Sealed Batteries

[nuxx]

Here's the thing... I *think* you could, but unless you properly take into account the amperage of the batteries and such, you could risk damage to the circuitry which handles the switching. And that would be bad...

That reminds me of how once when working retail, this guy came in and asked me how many deep cycle batteries he could chain off an APC BackUPS. He wanted literally racks and racks of them, so that he could handle his whole house. All while having things switched by that little BackUPS...

I'm not sure if you've ever been in a server room, but the UPS' to handle switching massive loads like this tend to be multiple-rack-sized, having contacts that look more like copper paperback books jutting out of the panel.

APCUPSD

[spikestabber]

If your using an APC ups, apcupsd is by far the best one to use. www2.apcupsd.com/

Re:Not sure if entire relavent

[spikestabber]

I've ran computer switching power supplies off of 110V DC (Direct current) before. Since their internal switching unit does not need the alternating current anyways. The AC is just converted to DC and filtered with a couple large capacitors, so feeding it DC will work just fine.

Battery info

[belg4mit]

Actually, if the UPs is worth a dam the backups aren't on a trickle charge; it should be periodically testing and charging as necessary.
Deep cycling is bad for any battery, but excercising them extends their life. I recently came across an interesting resource when doing
my own research on batteries

http://www.buchmann.ca/default.asp

apcupsd

[AllMightyPaul]

I like http://www.apcupsd.org to handle my APC UPS on Linux. It works very well, and also supports some Belkin UPSes.

Link to DIY-UPS instructions, general info

[pro-mpd]

http://www.dansdata.com/diyups.htm

For those familiar with Dan, you know that it's bound to be interesting. What he does is somewhat of the solution described in some comments.... battery charger, batteries, inverter. He also talks about the merits and pitfalls of different batteries in UPS systems.