Help with rack UPS (uninterruptible power supply)

[zzgus]

When I bought my second hand rack the guy give me a RACK UPS for free.

 

I have read the manual and done some tests but I think the batteries doesn't retain the charge.

As I'm not an expert I would like to get some help on how to proceed.

As you will see on the images there are a lot of batteries.

 

How can I really check the status of the batteries?

How can I know if the problem are the batteries or the electronic that charge the batteries?

For a single computer, could I replace all the batteries (in the case of defective) for only one or two?

Do I throw all and buy a simple new one?

 

Thankyou
gus

 

[1812]

If that operates anything like my big APC units, then the system won't turn on if the batteries are bad. If it has sat for a while not plugged in, that can kill the batteries. You can try leaving it plugged in for 6 hours or so and see if it will turn on after that. If not, chances are it is dead batteries. But this is no guarantee, it could be batteries AND the unit failure.

 

You can get a volt meter and measure the amps, if the batteries have any output.

 

When I got my large units, they were basically free but I had to replace the batteries. I went with battery sharks.com since I needed a bunch and they were the cheapest with the best warranty. If you don't find your model, then use the battery number/voltage/amps.

 

If you're running a single computer, it may be cheaper to just get something newer/smaller. 

[zzgus]

@1812

 

Quote

If it has sat for a while not plugged in, that can kill the batteries

 

Then it's almost sure thats the reason of the dead bateries.

 

Quote

You can try leaving it plugged in for 6 hours or so and see if it will turn on after that. If not, chances are it is dead batteries

I had it for 2 or 3 days charging , when I cut power, the old computer attached to the UPS did also power off.

 

Quote

You can get a volt meter and measure the amps, if the batteries have any output.

 

As the batteries doesn't retain charge, perhaps I can place the volt meter at the input of the batteries to test it?

 

Quote

When I got my large units, they were basically free but I had to replace the batteries. I went with battery sharks.com since I needed a bunch and they were the cheapest with the best warranty. If you don't find your model, then use the battery number/voltage/amps.

 

I have found locally at 24€ / 29$ each. What I don't know is if with one or two batteries how long will the server be alive?

 

And what UPS can I buy for the price of one or two batteries?

 

Thankyou
Gus

 

 

 

 

 

 

 

[1812]

22 minutes ago, zzgus said:

And what UPS can I buy for the price of one or two batteries?

 

Not sure about where you live but they make ones capable of up to 4-5 minutes runtime for about 100USD.

[S80_UK]

3 hours ago, zzgus said:

@1812

And what UPS can I buy for the price of one or two batteries?

 

Looking at the photo, it looks as though the eight batteries are connected in series - that strongly suggests that it won't work at all with only one or two.  You'd need all eight, and even if they were relatively cheap the UPS might still not work, or might not work well enough in terms of communcation with the server.  I think I'd go for a regular APC or CyberPower unit. 

[zzgus]

12 hours ago, S80_UK said:

 

Looking at the photo, it looks as though the eight batteries are connected in series - that strongly suggests that it won't work at all with only one or two.  You'd need all eight, and even if they were relatively cheap the UPS might still not work, or might not work well enough in terms of communcation with the server.  I think I'd go for a regular APC or CyberPower unit. 

 

Yes, the eight are connected in serie.

 

Are you completely sure that the unit will not work with only one or two ?

 

Thankyou
Gus

 

[pwm]

Lead-acid batteries are charged by a voltage-controlled charger. You really need to find the specifications if this UPS would be able to handle a 24V chain instead of a 96V chain. But it seems strange of they develop a powerful UPS and then makes it support being run as a junior-edition UPS.

[zzgus]

28 minutes ago, pwm said:

Lead-acid batteries are charged by a voltage-controlled charger. You really need to find the specifications if this UPS would be able to handle a 24V chain instead of a 96V chain. But it seems strange of they develop a powerful UPS and then makes it support being run as a junior-edition UPS.

 

I don't think this will be easy to find.

 

Gus

[S80_UK]

2 hours ago, zzgus said:

Yes, the eight are connected in serie.

 

Are you completely sure that the unit will not work with only one or two ?

 

Yes, I am as sure as I can be.  I could not see the exact model on the manufacturer's web site, so I could not find documentation.  The nearest equivalent range I could see was this....  https://www.salicru.com/en/ups/slc-twin-rt.html  They are rated from 700VA up to 10kVA - that's huge,  If you have the model number you can try searching for that, or even contact the manufacturer to see if they can provude the documentation.

 

As @pwmsays, the charger will be a voltage controlled charger, so it will not normally be designed to handle a smaller number of batteries. 

[JonathanM]

You will definitely need the same number, but you might possibly get away with an equal number of smaller Ah batteries. Pretty much any SLA 12V should work to some extent. Honestly, looking at the pictures, I think the spec for the unit is probably for 8 much larger batteries.

 

Unless you really know what you are doing, all batteries should be replaced at the same time, regardless of how many are bad. If you want a quick and dirty test, an automotive brake light bulb rated for 12V makes a decent load tester for individual batteries this size. Look for uniform brightness.

 

I would LOVE to get my hands on a unit like that for cheap, that thing should have some serious runtime with a good set of batteries that fill the available space. I'd bet 2-3 hours solid for a fairly efficient server.

[pwm]

5 hours ago, jonathanm said:

Honestly, looking at the pictures, I think the spec for the unit is probably for 8 much larger batteries.

Yes, I'm pretty sure the photo is with smaller batteries than it was originally designed for.

 

The brackets can't manage to clamp down the current batteries and there is just so much free space in there. The current batteries are 7Ah each which means about 700 Wh total capacity. With the correct batteries I would expect at least 1500 Wh .. 2000 Wh total capacity.

 

8 times more battery capacity than a "normal" UPS means way more than 8 times more runtime at the same load.

 

So this is a beast of an UPS. But at a very premium cost when it's time to buy a full new set of batteries.

[zzgus]

1 hour ago, pwm said:

Yes, I'm pretty sure the photo is with smaller batteries than it was originally designed for.

 

Those are the "original" batteries.

What I have done is remove the clamps and put the batteries upward.

 

The other problem is that I don't have the cable that comunicates this UPS unit with the server.

Do you know if it's a "standard" cable I can buy anywhere?

 

Thankyou

Gus