Cyberpower 1285AVR (CP1285AVRLCD) reporting wrong battery voltage?

[Sean Devine]

UPS turned off one night and it seemed that the 3 year old batteries gave out.

Replaced with a new pair, but the UPS software claimed the battery voltage was only 18 volts and needed to charge. After 24 hours, the UPS claimed only 60% charge and 20 volts (although FWIW, my meter sees 27v).

...then I found various Cyberpower threads here with some guidance on what to check.

C1 (22uF) tested at 2, so I replaced that.

Put it all back together and didn't see a change on the reported battery voltage. Although, I did run the quick battery diagnostic test w/in the Cyberpower software--it passed and then claimed the batteries were fully charged.

I saw others pull C3 and C6 (33uF) and my meter claims 34uF.

Is the Viper22a the next thing to replace?

[sam_sam_sam]

Yes I would recommend replacing Viper 22a chip but when you do make your self an incandescent light limiting circuit tester and use in place of the fuse or in series on the hot side of mains power supply does the light bulb flash bright for a second or two and go dim or all the way off do you have voltage to the battery charging circuit

Use at least a 100 watt light bulb or higher up to 300 watts if the 100 watt light bulb is at full brightness hopefully it not at full brightness when you go to 200 watts if so go to 300 watts but if it is still at full brightness then check for short circuits on the primary side of the circuit