UPS - Tripp-Lite OMNIVS1500XL - No power when mains are disconnected

[fuxxy]

I'm honestly not sure where to go from here.
As the title says: Tripp-Lite OMNIVS1500XL UPS

I've replaced the batteries with 'known-good' out of one of my other UPS's. The unit will turn on, and supply power to the outputs. When mains power is disconnected, the whole unit turns off (along with anything connected to it).

I'm honestly clueless how these actually work.

FYI: Battery voltage is 13.04 & 12.83

[kc8adu]

Re: UPS - Tripp-Lite OMNIVS1500XL - No power when mains are disconnected

seeing the 2 batteries in different state of charge after being used in series is a red flag.
did you load test?
this 1500va unit may be more demanding than whatever you borrowed batteries from.
tired batteries are the most common cause.

[fuxxy]

Re: UPS - Tripp-Lite OMNIVS1500XL - No power when mains are disconnected

One is a battery from my FiOS ONT backup, virtually brand new. The other is out of another UPS that works.

[Ed Hall]

Re: UPS - Tripp-Lite OMNIVS1500XL - No power when mains are disconnected

The first thing I would do is to safely find a way to measure the batteries in the following three states:

1- stable state - totally disconnected
2- charging/maintaining charge - installed, with mains connected and unit on
3- under load - installed, with mains disconnected and unit on

From here, I would evaluate whether the different sections were operating. With mains available and unit on, there should be a slightly higher voltage than the stable state across the batteries. Under load, a slightly lower voltage, but it should not fall dramatically.

If you need to disassemble the unit to perform the tests, then by all means remove both the mains AND batteries prior to the disassembly. Still be careful - there are often some sizable caps within. Then, do a thorough visual inspection.

Let's start there. Maybe some others will chime in with better troubleshooting instructions.

[Behemot]

Re: UPS - Tripp-Lite OMNIVS1500XL - No power when mains are disconnected

Check if connection is tight (fastons are not loosy etc.) and there is no cold joint, under tens of amperes the voltage will drop immediatelly. Than crack it open and check fuses. From the voltage it does not seem the unit is even charging, is it? Charged batteries should have 13,4-13,8 V no load.

[fuxxy]

Re: UPS - Tripp-Lite OMNIVS1500XL - No power when mains are disconnected

Thanks for replies, guys

Turns out I believe one of my "known good" batteries are in fact bad. Even though voltage tests good after being charged by the working UPS, it still won't put out anything under load. Will replace bad battery and try again.

I took batteries out of /another/ UPS and installed in the OMNI1500, and it worked great. The tripp-lite UPSes require good voltage from batteries to turn on, that's why it wouldnt turn on when on the bench.

[Behemot]

Re: UPS - Tripp-Lite OMNIVS1500XL - No power when mains are disconnected

Probably too soft already. Voltage is not everything, it can be OK while having enormous ESR. It's like with capacitors. Actually it can became a huge capacitor

[kc8adu]

Re: UPS - Tripp-Lite OMNIVS1500XL - No power when mains are disconnected

just had an 08 apc with original batteries on the bench.a load test showed the batts to be marginal.
the unit would flunk its test and chirp annoyingly.
new ones fixed it.
btw i opened the old ones and added a bit of distilled water to each cell with a syringe.
they then load tested slightly better than the new powersonics i put in!
and even got good resuts on a 1a discharge test with a hobby charger.they were csb grays.
the vision ones from a second unit much newer were totally gone!