Most people who do anything serious with a home computer use a battery backup system or UPS (Uninteruptable Power Supply) to keep it running through power glitches, dropouts or brown-outs.
Simply, a UPS is a battery, battery charger, inverter and a switching system to transfer to batter power when needed. Without a UPS, the briefest loss of power will crash your computer and you will loose whatever unsaved data you were working on. In the worst case the computer can be permanently damaged this way.
Not many people know that, just like the battery in a car, a UPS battery has a finite lifetime. After a few years they no longer hold their charge and therefore the UPS can no longer perform its function.
Here is a typical UPS that I use on one of my machines.
During a recent thunderstorm I saw the AC power flicker and the machine connected to that UPS died. A quick check showed that the UPS was not working.
This particular unit has easily replaceable batteries and only requires the removal of two screws to gain access to them. Here is an image of the insides of the unit with the batteries removed.
Here is what the batteries look like (this unit uses 2).
Our local Batteries Plus store has replacements and, though not cheap, this is still less costly than a whole new UPS. If you try this yourself there are a few things you should remember:
- Be sure to purchase replacements that have the same voltage, ‘amp-hour’ rating and physical size as the original.
- Be sure the terminals are the same type and size as the original.
- Use care when transporting both the old and the new batteries. Cover the terminals with insulating tape because even ‘dead’ batteries can cause a fire if short circuited. The new batteries should come with protective covers on the terminals.
- Remember where to reconnect the wires when you install the new batteries. Taking a digital photo before removing the old ones will help you know which wire goes where.
- The store should take the old batteries for recycling. Don’t put them in your regular trash!
- Not all UPS units are equally easy to work on. I have one (from Belkin) that requires lots of effort to disassemble and reassemble. Other units advertise “User Replaceable Batteries” and are very easy to service.
To check to see if your UPS needs new batteries, shut down your computer and connect something else, such as a 100 watt lamp, to the UPS. Then see if it will stay lit when the UPS is unplugged from the wall. Some units will have a ‘test’ function or an indicator light when batteries need replacing.
If you are reasonably handy and have a few basic tools this is an easy project and can save you trouble and dollars.