Smart-UPS 5000 wont power on

[Anonymous user]

Hi,

I've got an APC Smart-UPS 5000 (SU5000I), serial number starts with CS0422, which wont power on. No LEDs, no BEEPs, no nothing.

Two of the 4 battery packs are swollen, and I suppose that all the batteries are old enough that they should be replaced, however I'd like to know if the UPS is in good working order before spending the money.

I tried already to remove the battery packs and connect to mains, UPS remains off/silent, "On" button doesn't do anything.

Is there anything I can do to find out if the UPS is dead?

Thanks,

-jgp

[BillP]

It's hard to say going based on what you have said so far.  The batteries' failing in general should not cause a UPS to not turn on however if the batteries are COMPLETELY discharged, the UPS may not turn on.    You have done all the testing we can recommend at this point.  This UPS is about 8.5 years old so I would personally recommend you trade up to a new UPS as the batteries for this UPS are pricey.

[MicDiFebo_apc]

Hi,

I'd like to reactivate this old thread because we also have this old UPS in our small LAB and it wasn't used for years and now we have the same symptoms as Chris.

The SerialNo is SU5000RM15U - CS0345111847.

Beside the discussion whether it is reasonable to buy a new device or new batteries I'd like to know, how the UPS normally shall react if no single battery is in and the main power is switched on.

As Chris mentioned no LED is light or flashing, no beeps and the "fuse" on the backside is "in" which should be the case i guess.

Is there any other fuse inside the box?

Can anybody shortly describe what normally happens in this case?

Thanks in advance

Greetz

Mic

[BillP]

Hi

This range of UPS require battery voltage to turn on, so if the batteries are below a certain voltage threshold or absent the UPS will not turn on.

Regards

Matt

[MicDiFebo_apc]

Hi Matt,

that is a very useful and quick answer - thanks.

Just an idea - we do not need the complete power of that UPS - so I want to buy only half number of batteries. Is far as I saw, the four battery-pack are packed together as 24Volt each and then I guess the four packs are in series so that we have 96 Volts internally at the end - right?

That means 8 batteries should be sufficient to get the UPS running - two in series in each Slot.

Greetz

Mic

[BillP]

Hi Michael,

This UPS uses a nominal 48v battery system with modules comprised of pairs of 12v batteries. We do not recommend running the UPS with anything less than the full compliment of batteries.  The unit you have is 16 years old, which is beyond the typical lifespan of a UPS. I would be hesitant to invest too much money in it.

Liam

[MicDiFebo_apc]

Hi Liam,

thanks for this additional explanation.

Of course it is an old device but in times where sustainability plays a big role I'm not going to exchange a system which still works fine. It is very helpful in this particular case, that we only need it for a rack with some lab-equipment - no production environment. Therefore I also do not need the the complete original power of the UPS and thought about populating it with only half of the batteries, which should work in general. And it is much easier for me to order some additional batteries in context with a substitution of those in our really important systems than to order a new device.

Because of having a 48V System it seem to be enough to have only four batteries - right?

Michael

[BillP]

Hi Michael - 

I can only recommend our specified battery solution, which is (Qty 2) of our RBC12 replacement battery cartridges. 

thanks

Liam

[BillP · Accepted solution]

Hi could you please tell me If you tried it and it worked with 4 batteries?because I have the same problem.I want to avoid buying the 16.

best regards 

[MicDiFebo_apc]

Hi Vaggelis,

until now I haven't bought those batteries, but I will give it a try and keep you informed.

currently I have another project therefore I didn't workes that much on this issue. But I opened the enclosure to see how it is wires internally and it is fact, that the two battery-packs of one of those slots are wired in series. Each pack consists of four batteries - two in parallel and this two in series with the other two. Over all 48 Volts per side.

That is the same with the other side, but the further cabling is not that easy to dertermine.

I will try with 4 batteries and if that also does not work, I will spend another four for the other slot. For test-purposes I already have two batteries from smaller UPS.

Regards

Michael

[BillP]

thank you very much for your reply I will be waiting

best regards 

[MicDiFebo_apc]

Hi @ll,

i managed to get some slightly used batteries for some experiments on this device.

In fact it works as soon as you put in at least four batteries.

But take care to wire each two batteries in series, and connect this two battery-packs each with the internal (big) power-connector in the UPS. This connectors are also wired in series that means, that you have 48V in total, which is enough for the UPS to work. I hope to have it explained in an understandable way 🙂  

Btw. I opend the device to check the internal wiring. Both slots (each delivering 48V) are terminating on a PCB. I assume there is a kind of load-balancing or backup realized with this part of the circuit - but that is just a guess.

Although four is enough to get the device working, I will now try to get eight batteries in total to have each slot equipped with four of them just in case that this is relevant for better performance during a power-loss.

I haven't made any long term tests so posting this is just a quick snapshot. I only tested a power loss with a 3D-printer connected (maybe 120W load).

Cheers

Michael