Testing APC UPS without recommended batteries

[sairfan1]

I have couple of APC UPS (different models with different output power and battery requirements) without batteries and I want to test them if they are working I will buy new batteries for them.

Can I use above the rated power for example if required battery is 12v 4A can I use 12v 8A?

I have HP-6543 power supply can I use it instead of battery like setting 12v 4A on the power supply and use it as a battery?

What other methods can be used to test such UPS.

[agehall]

Yeah, the capacity of the battery won’t matter for testing.

You can also use large capacitors to jumpstart the UPS - seen people on YT do this. But imho, it is easier to just hook up batteries.

Do note that depending on the model of your UPS, you may have to go in and reset some variables. My APC UPS still thought I had 1 minute of runtime after replacing the batteries and had to have some internal setting changed before it would calculate the runtime correctly.

[edpalmer42]

I've seen some APC UPSs that will appear dead if they don't have a battery installed.  But if you connect a simple little wall wart, it starts up fine.  It just needs a tiny amount of battery voltage to allow it to wake up.

Once it starts up, you can talk to it, configure it, whatever.  It might be able to provide voltage boost and cut functions if those don't need a battery.  Some UPSs use the battery for voltage boost, some don't.

Larger batteries are fine, up to a point.  If you install a huge battery, you might burn out the battery charger circuitry since it would be pumping out maximum current for days trying to charge the behemoth.