UPS fixing

[menash]

Hi, I got a not working UPS -advice prv650- to my hand and i'm trying to fix it.
When I connecting it to the main it stays off and none of the light are turning on. I opened it and I couldn't found any damage component, only the battery is dead. so I got the idea to replace the battery with my 12V power supply and see if it work on battery mode (disconnected from the main). it worked, and i measured 230V on the output.

now is it ok to connect it to the main when my power supply is replacing the 12v battery? i want to make sure that the problem is the battery only.

thanks!

[EHT]

That would depend on whether the PSU and / or the UPS inverter are isolated. Unadvisable unless you are very confident about that.

How about charging the battery up then trying it in the UPS. If it won't hold charge then its faulty, needs replacing and is likely to be the only problem. If it does hold charge and run the UPS then it would show there is a fault in the power supply of the UPS.

[menash]

Thank you, I will try to get battery to check that

[gnif]

Most UPSs do not power on if the battery is completely dead, it is a safety feature.