Best options for long term (~9 months) storage?

[Anonymous user]

I have a trio of DLA3000RM2U's that I'm about to replace the batteries in. For the moment, there will be no loads present on these units. They won't see any loads for the next 7 months.

What is the best way to preserve the life of the cells? My initial thoughts are to install the batteries, let them charge for 48 hours and then disconnect the cartridges so they don't risk over charging.

Thoughts?

[Anonymous user]

I'm not familiar with that model. The one step I'd add is that after shutting down and disconnecting the UPS from input power, but before unplugging the batteries, press and hold the "Off" button until the UPS clicks. APC refers to this as "dead-ing the UPS" and is the polite way of telling the electronics "OK, we're *really* turning off now".

I'd be somewhat concerned about the batteries sitting idle and uncharged for over 6 months. The battery manufacturer should have "discharge vs. time" graphs in the data sheet(s) for the battery which will provide better info.

If you're going to replace the batteries and place the units into storage, why not disconnect the existing batteries, put the units into storage, and then replace the batteries once you have a need for the units again?

[Anonymous user]

The DLA3000's are 3000va 2U rackmount Smart-UPS's. Quite nice, especially considering I got the 3 of them for $300 total, all with management cards, too (we're a non-profit, so I shop used when I can).

As to why I have to replace the batteries now, it's budgetary reasons. I need to replace them while I can get the budget to do it. Come September when I need to use them, the budget will be blown by others and I won't have the few hundred bucks to re-cell them (we operate a haunted attraction and only run mid September through early November).

Something I didn't mention, power is available, so I can keep everything plugged in if need be. I just wasn't sure if it was better to keep the batteries plugged in, constantly charging or if it was best to unplug them. If it's ideal, I can unplug them and replug them for a top-off once a month or whatever the recommended time frame might be.

[Anonymous user]

Well, they don't charge constantly - they should float and only get topped up if the voltage is low. Either leaving the UPSs plugged in and running or powering them up for a day each month would work - which is better depends on how much you pay for electricity. Note that if you forget to disconnect the batteries after the monthly charge, you will kill the batteries, so I'd go for "on all the time" if that's possible for you.

[BillP · Accepted solution]

You may want to look into this FAID [Battery Discharge During Storage|http://infomanager.schneider-electric.com/itb/index?page=content&id=FA156516]