Add standby time to a cheap UPS

In South-Africa we often experience load-shedding! Its an irritating emergency plan created by the countries one and only power company called Eskom. Most people refer to them as “Eksdom” which mean “I’m Stupid”. Different suburbs get load shedding at different times to conserve power.
Seeing I’m a guy with a plan, I off coarse want a way to reserve some power to run things when the power grid goes down and came up with this.

I’m simply removing the battery of cheap 460 Watt UPS meant for a PC and adding a much bigger battery to it. Originally this UPS came with an internal 7Ah battery and I’m replacing it with a 102Ah. If you have a couple of boken UPSs laying around. Don’t throw them away just yet. Use the UPS rated at the highest Wattage you can find.



Remove the screws and open it. Let’s see whats inside.



After removing the screws I had to unplug the front cover and it all came apart.


You MUST first remove the battery!, If you dont you stand a very good chance of getting an electrical shock which can be fatal! Be very very careful.

Pulling off the terminal is not that hard, once you have taken out the battery discard it. If the UPS wasn’t working before you opened it 99.9% of the time its because the battery is faulty. In my case I could see visual damage on it. The battery serves a good weight for random project stuff.


Most PC UPSes have a buzzer that will beep at a set interval when running from the battery and not the mains. This off coarse is very irritating. I used some long nose pliers to break off the buzzer. Use a soldering iron to take it out if you must. But my way of doing it is way quicker.

removebuzzerremovebuzzer pliers

Extend the wires (Not shown) so that they are long enough to reach an external Deep Cycle battery.Drill some holes and put in some grommets to make it look somewhat neat.


Once you have extended the wires, BE SURE TO MARK THEM POSITIVE and NEGATIVE WITH SOME BLACK TAPE, This is very very important, If you don’t and you switch the terminals it will blow up and cause a fire.

close it all backup

You will also need a multi plug that plugs into the UPS, Used a multi plug adapter and replaced it’s plug with a Male kettle cord from a kettle cord extender. Make sure you use the Male part of it as shown in the picture.

make a multiplyg

I placed the battery connected to the UPS inside my TV Cupboard. When running from UPS power I open it for some air flow in-case things get hot just to be on the safe side. It generates some heat but nothing serious.


Some Problems with this setup.
The original battery was only 7Ah, It was swollen, and there is a big power difference between  7Ah from old battery and 102Ah of the new battery.

This means the internal charger of the UPS is not meant to charge a 102Ah battery. Also the fact that the 7Ah battery was swollen and after opening a couple of other old PC UPSes of different makes they all suffered the same fate. This tells me that the charger is a trickle charger which applies power to the battery all the time even when in running off of the mains.

This setup allowed me to run a 100Watt TV and Satellite Decoder for 3 hours, after it was charged again. It lasted 2 hours and again after the second full charge it lasted only 45Mins. So the UPS internal charger degraded the battery very quickly. I since then stopped plugging the UPS into the mains. And bought a Smart Micro controlled charger that has a decent charging plan. I went for the Optimate5 Voltmatic


Instead of a Ctek charger purely because of the price difference. I’m going to sound like an Optimate Sales person. I can absolutely vouch¬† for this charger, It gets the Job done perfectly and its now permanently charging the battery. Its been a year after building this and the UPS still runs for 3 hours on the 102Ah battery. Using a smart charger is most definitely a must.

See below video for more clarity on this build.

Have fun and stay safe , remember 110V or 220V AC is deadly! If you have never worked with mains power don’t try this as home.

If you liked the video then maybe you will also like some of my others. Subscribe to my YouTube channel and you will be notified about my future projects.
Until then see ya later!

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