UPS loses charge capacity in 3 months

[Anonymous user]

I have APC UPS RS500 (500VA). The only load I connect to this UPS is my modem/router rated 700ma@12V (appx 10W, I think). I switch on the UPS only when I need to use my modem, else it is switched off. The power supply to UPS is always on.
The UPS when bought new used to provide back up power to Modem for more than 6 hours. In less than 4 months, the UPS has lost it's charge retention and now can only provide back up for 15 mins (in the event of power failure of course). This has happened with my second UPS now (first one got it replaced for same problem).

Could somebody let me know what am I doing wrong or provide hints ? I would really appreciate your help.

Thanks,
Green_ga

[BillP]

Actually it should always be charging as long as it is connected to utility power, whether or not it's turned on. The manual should specify this.

Unfortunately though, I don't really have any ideas in terms of abnormally short battery life you're seeing...

[Anonymous user · Accepted solution]

I have APC UPS RS500 (500VA). The only load I connect to this UPS is my modem/router rated 700ma@12V (appx 10W, I think). I switch on the UPS only when I need to use my modem, else it is switched off. The power supply to UPS is always on.
The UPS when bought new used to provide back up power to Modem for more than 6 hours. In less than 4 months, the UPS has lost it's charge retention and now can only provide back up for 15 mins (in the event of power failure of course). This has happened with my second UPS now (first one got it replaced for same problem).

Could somebody let me know what am I doing wrong or provide hints ? I would really appreciate your help.

Thanks,
Green_ga