You bought a Uninterruptible Power System (UPS) a year or two ago and now when you get a power cut your computer switches off instead of running on the UPS battery power. What’s wrong? Your battery is all worn out.
You can easily replace your UPS batteries instead buying a new one and at a fraction of the cost. UPS manufacturers would of course prefer that you replace your entire UPS when the batteries die, since they make more money that way. But in fact there is nothing unique or magic about UPS batteries. They are standard types with standard connectors. You can buy them from sources other than the UPS manufacturer, and sometimes replace them with equivalents that are better and less expensive.
Do not throw old batteries in your regular trash! They contain toxic metals and acids. Be kind to your environment and hand them to a qualified party for recycling. Most battery dealers will cheerfully do this for you. If not, your local garbage company or waste-disposal authority can explain to you how and where to turn them in safely.
Many UPS models use gel-cel batteries in standard formats like 12.0 V, 7.2Ah (151x64x94 mm). Warning: Many manufactures sell two or three different types: standard use, cyclic use and high-current use. Take your old battery from your UPS to your supplier or take a phone of the battery label to show and you can be sure you will get the correct replacement.
Be careful depending on the model of your UPS you may have to unscrew the protective case make sure the unit is unplugged and switched off. Even then be extra careful don’t forget the UPS is designed to convert the 12volt battery power to mains voltage touching the wrong parts could give you a nasty shock.
It may take several discharges and recharges of new batteries before they reach full capacity and the calibration is accurate.
Some UPS’s will connect to your computer and or have internal monitoring which may show warnings after your battery change see the manufacturers website for details on how to reset these.