IBM 3000VA UPS - How to test UPS / batteries (not just voltage)

[Belix]

Greetings all
I've been using an old (2010) IBM 3000 VA rack UPS to power just a 50" LCD and decoder.
It was fine through the 4 hour load shedding, but somehow since the 2 hour load shedding, now dies after about an hour, even with the TV off. It still shows around 2 hours capacity remains, but then issues a battery low alarm and shuts down.

I checked the 8-in-series unit battery pack and found two of the Yuasa NPW45 12V batteries were about 10V.
Swapped them, and two swollen batteries out with 4 new of the same make/type Yuasa NPW45 12V 8.5Ah batteries. (since then I've been told I should not mix old and new batteries, but anyway, that's what I did). They are not a cheap purchase at R1K each...

Thereafter, the UPS does pretty much the same thing, I get about an hour. All batteries show about 12.5V each when it shuts down.
I went into a store that sells inverters, and they said to replace all 8 batteries with their al-cheepo R250 versions.

I was wondering if I should risk buying another 4 of the OEM Yuasa batteries instead, but given the cost, would like to check the UPS is not the issue, but not sure how to without 1st buying another full set of batteries.

Would checking the capacity of the batteries one at a time using some sort of battery tester reveal if any of the remaining 4 are showing 12V, but have hardly and Ah capacity left in them?

 

[ADrunkTeddyBear]

Its most likely the new batteries derating to the capacity of the old batteries.

You can test each battery by applying a load to it and seeing how long it takes to go flat and from there you can get an idea of its capacity e.g. getting something like a 12V 4A motor (thats around 50W) and running it should last you give or take 2 hours

 

[wingnut771]

Greetings all
I've been using an old (2010) IBM 3000 VA rack UPS to power just a 50" LCD and decoder.
It was fine through the 4 hour load shedding, but somehow since the 2 hour load shedding, now dies after about an hour, even with the TV off. It still shows around 2 hours capacity remains, but then issues a battery low alarm and shuts down.

I checked the 8-in-series unit battery pack and found two of the Yuasa NPW45 12V batteries were about 10V.
Swapped them, and two swollen batteries out with 4 new of the same make/type Yuasa NPW45 12V 8.5Ah batteries. (since then I've been told I should not mix old and new batteries, but anyway, that's what I did). They are not a cheap purchase at R1K each...

Thereafter, the UPS does pretty much the same thing, I get about an hour. All batteries show about 12.5V each when it shuts down.
I went into a store that sells inverters, and they said to replace all 8 batteries with their al-cheepo R250 versions.

I was wondering if I should risk buying another 4 of the OEM Yuasa batteries instead, but given the cost, would like to check the UPS is not the issue, but not sure how to without 1st buying another full set of batteries.

Would checking the capacity of the batteries one at a time using some sort of battery tester reveal if any of the remaining 4 are showing 12V, but have hardly and Ah capacity left in them?

This is the wrong thing to use for long power draws as you are finding out as the batteries in these UPS's are only meant to supply power for 10 minutes. You need deep cycle (and still only use 50% capacity) or lithium batteries.

You will just be throwing good money after bad if you continue down this path.

 

[Belix]

Its most likely the new batteries derating to the capacity of the old batteries.

You can test each battery by applying a load to it and seeing how long it takes to go flat and from there you can get an idea of its capacity e.g. getting something like a 12V 4A motor (thats around 50W) and running it should last you give or take 2 hours

Thanks, I’ll look into this. Was looking at a battery tester but they seem to be mainly automotive.

This is the wrong thing to use for long power draws as you are finding out as the batteries in these UPS's are only meant to supply power for 10 minutes. You need deep cycle (and still only use 50% capacity) or lithium batteries.

You will just be throwing good money after bad if you continue down this path.

Thanks for this, did not even cross my mind to check if they were deep cycle or not, just assumed they would be.
Would lithiums work with a UPS not designed for them, even if they had a built in BMS?

 

[wingnut771]

Thanks, I’ll look into this. Was looking at a battery tester but they seem to be mainly automotive.



Thanks for this, did not even cross my mind to check if they were deep cycle or not, just assumed they would be.
Would lithiums work with a UPS not designed for them, even if they had a built in BMS?

The lead replacement types would work, alrthough now that I think about it, I'm not sure how their BMS's would like it when they are connected in series as these are designed for gate motors and alarms etc so it would be an expensive experiment.

Honestly, you're better off getting something like this:

cloudlink

Available on Back order Next available stock 31/07/2022 HUBBLE LITHIUM S-12012.8V 1.5KWH• High Cycle Life and Service Life• High Performance Lithium battery• Internal Battery Management System• Excellent high temperature performance• High energy density and conversion efficiency• Can be...

powerforum-store.co.za

Synapse UPS 600W 12V DC - 230V AC, pure sine wave

Synapse 600w UPS Inverter: The Synapse 600w UPS is designed to work and protect electronic appliances and serves as a backup device in extremely hostile power environments. It comes with an AC input that allows the battery bank to be charged through the grid (cable included). An extra-wide input...

powerforum-store.co.za

Spend R5k on one battery (and have the option to scale it up as it can do parallel and series) and get 1200Wh instead of taking a gamble on multiple small batteries (only around 100Wh each) and have nowhere near the same capacity.