Used UPS + new battery

cenerth · 28 Jan 2022 at 13:18

Hi,

During this winter I just had a 3rd power outage. Thought it was a good time to buy a UPS, I need it for CCTV + home network (routers, switches). All of these devices consume about 25W in total, not really that much.

What do you think about buying an used UPS plus a new battery?

I was thinking about something like:

- UPS APC Back-UPS CS 500 - used one, without battery for $20 with warranty for a few months.

- new battery: Alarmtec BP 7-12 (12 V, 7 Ah, 2,05 Kg) I can get it for $15.

I don't really need much but it would be nice to have some backup (extra power for at least a few minutes).

andy_mk3 · 28 Jan 2022 at 13:22

that's exactly what I have done with my APC UPS', bought them working with old batteries and bought cheap generic batteries and they perform well.

ANDARIAL · 10 Feb 2022 at 08:43

andy_mk3 said:
that's exactly what I have done with my APC UPS', bought them working with old batteries and bought cheap generic batteries and they perform well.

similar to me ,i just fit new batteries after about 2 years to all my UPS
You can get higher AH batteries in same physical size now about 9AH iirc

sithlord · 3 Mar 2022 at 11:56

They dont last long even with new batteries. Due to the aging capacitors.

I bought 2 different branded UPSes and they both died in 2 years.

EsaT · 3 Mar 2022 at 20:09

sithlord said:
They dont last long even with new batteries. Due to the aging capacitors.

I bought 2 different branded UPSes and they both died in 2 years.

Would be propably better to change also those.
Can imagine how badly built some UPSes are when even APC has Chinese garbage capacitors in their UPSes.

Phil2008 · 30 Mar 2022 at 12:20

I have a "generator friendly" online UPS that I use to power my main room with, so when the power goes off, Im not in the dark. And have 1-2hrs before the battery dies, so have loads if time to get the generator up and running. But with the UPS using 20-40watts with monitoring the incoming power 24/7, Im only using the UPS with my 3d printer atm due to electric prices rocking next month :mad:

But yeah if its a used UPS I would replace the batteries.. And remember to buy a over the top high wattage UPS if you want it to last a longish time during a powercut.. Like mine is 1800watt but I only use a max of 300-400watt, but it last a decent amount of time in a powercut.

This is mine, it was £350, but if it was a well known brand with those specs, it would be over a grand easy Id say...... Designed in Germany but made in China , to cut costs no doubt. :mad:

https://powerwalker.com/?page=product&item=10122042&lang=en

Phil2008 · 30 Mar 2022 at 13:04

EsaT said:
Would be propably better to change also those.
Can imagine how badly built some UPSes are when even APC has Chinese garbage capacitors in their UPSes.

These are the caps in mine and Im guessing their rubbish Chinese caps.........

EsaT · 30 Mar 2022 at 14:23

Phil2008 said:
These are the caps in mine and Im guessing their rubbish Chinese caps.........

Can't say anything from that fuzzy pics.
Though looks like those big inverter feeding/input filtering bulk capacitors might be made by Aishi.
If true at least some of those smaller ones are likely also Aishis.
While no top maker, it appears to be pretty decent for the price.

Phil2008 said:
This is mine, it was £350, but if it was a well known brand with those specs, it would be over a grand easy Id say...... Designed in Germany but made in China , to cut costs no doubt.

Suspect more like specs, colours and cardboard box designed in Germany...
But who removed the fans?

Hotwired · 30 Mar 2022 at 14:25

Could be manufacturing cost cutting, just like not putting in all designed screws. As long as the failure rate is ok, keep skipping parts :eek:

Phil2008 · 30 Mar 2022 at 16:42

EsaT said:
But who removed the fans?

I swapped them for slow quieter fans, as they were far too noisy for 24/7 use, but the UPS thinks the fans are faulty because they are slower, but thats fine as its just a red reading on the screen and no annoying beeping noise. Even though the fans are slower and dont move as much air, it hasn't made much difference as the case always feels stone cold..

But its only about 10% loaded and I use it as a regular UPS so the inverter is only in use when its 5% out of the 240 voltage range, as it uses less power in this mode (about 10watts less, but every little helps). But when its connected to the generator it always uses the inverter to keep a solid 240 as the volts are not as constant and stable with generator power, unlike mains power.