How to keep a shelved UPS (which will be used rarely) active so it will perform well

[plainman007]

Hi,

I have bought a new UPS which i will be using only 3-6 times in a year. This is to be used with a pc which will only be used on the field to control some automation. The rest of the time the PC will just be shelved in storage. Now that means almost 3-4 months of just being in storage. If i just disconnect the UPS and store it will the Sealed Lead Acid battery which is inside get spoiled or die due to deep discharge ?

So what is the better solution, to leave it plugged into the ac mains always throughout the year, even without any load attached to it ? Some say this will cause the battery to heat up while others say its normal / better.

Some have suggested connecting some small appliance to it, like a bulb or something and to use it continuously.

Please give me some suggestions ?

Thanks

 

[iop95]

Better is to conect UPS one time on month for 24 hours to recharge battery. If is not possible, keep it connected, without any load.

 

[BradtheRad]

A battery is better off when kept fully charged (even if unused). Left disconnected, it will self-discharge over a period of a few weeks. Then when you need the unit, the battery will not be ready, and you will have to charge it.

The battery chemistry ought to be exercised every so often. Otherwise it may develop sulfation, which reduces its capacity.

You need not discharge it entirely. Cycle it every month or so (per post #2).

Whether cycled often or seldom, you can expect battery life to be 3 to 6 years.

 

[iop95]

Voltage discharge to minim accepted (to avoid battery demage) may be found in battery datasheet and for VRLA is about 12-20 mounths. If system is used 3-6 times per year maybe know with 1-2 days in advance and may put UPS to fully charged. No need to keep UPS all time connected, it's waste energy, except don't know when you need system and need to be ready at any time (emmergency working mode).

 

[chuckey]

Traditionally to keep lead acid batteries up to voltage, a "trickle" charge used 13.8V for 6 cells as opposed to 14.2 to fully charge. Or 15V for the latest Chrysler alternators (Yikes) :-o

Frank