VRLA or AGM battery in a UPS, chances of being able to recharge?

[ericmark]

I found a 120 volt 60 Hz UPS I had been given, been sitting for at least 3 years, more likely 5 or more, the battery is dead, as expected after that time, I would guess around 7 AH, 12 volt, not sure if I have any use for a 120 volt 60 Hz power supply, but thought would try and charge up the battery.

As zero volts, my smart charger will not charge it without cheating, so put it in parallel with a 12 Ah power block, so the charger will work, seem to remember doing this in the past, and took 2 weeks before the battery responded, so what do you think are my changes.

 

[flameport]

Somewhere between impossible and not going to happen.

If you place any value on your time and effort at all, buy a new battery for £12.

https://cpc.farnell.com/pro-elec/pel01436/battery-lead-acid-12v-7ah/dp/BT06696

 

[ericmark]

I also think unlikely, however also intrigued as to if it will or not, even if it does recover, not sure what I would do with a 120 volt 60 Hz supply, so not worth buying a replacement.

 

[mikeyd]

I don't think anyone has use of an old UPS with old batteries. Much less one that is 120V. Obviously the 50/60 Hz isn't an issue. I would politely advise you to just get shot of it.

 

[sparkymarka]

Too much time on your hands …

 

[JohnW2]

I don't think anyone has use of an old UPS with old batteries.

... and rightly so. As I recently observed, a UPS with an old battery is a 24/7 energy-guzzler

Kind Regards, John

 

[Harry Bloomfield]

Too much time on your hands …

But nothing wrong with having curiosity...

A great deal of modern electronic equipment is designed for 130/230v 50/60Hz supplies, especially desktops and laptops. Input wise, it would need a transformer at least.

 

[ericmark]

It is curiosity, removing the donor 12 AH battery the Lidi smart charger goes over voltage and switches off, but shows 9.6 volt, so some energy entering the battery, the 12 AH battery would be on charge anyway, and the power from mains is shown as 2 watt, so very little, just interesting to see if it recovers.

Some where I have an auto transformer from a 110 volt fluorescent light, so could transform the voltage, but its the 60 Hz which is real problem.

 

[JohnW2]

Some where I have an auto transformer from a 110 volt fluorescent light, so could transform the voltage, but its the 60 Hz which is real problem.

I'm not sure that, in practice, that is likely to be a 'problem', is it?

Kind Regards, John

 

[Harry Bloomfield]

I'm not sure that, in practice, that is likely to be a 'problem', is it?

An SMPSU, which is what a UPS will usually have, will not care too much about input frequency.

 

[JohnW2]

An SMPSU, which is what a UPS will usually have, will not care too much about input frequency.

Quite so. It really should not care hardly at all. Having said that, at least some of the UPSs I've seen inside have conventional (large transformer) PSUs - but they probably won't care too much about the frequency difference, anyway.

Kind Regards, John

 

[Harry Bloomfield]

I've seen inside have conventional (large transformer) PSUs - but they probably won't care too much about the frequency difference, anyway.

Efficiency will be a little less and a little more heat generated, but not usually an issue.

 

[Astra99]

Most, if not all IT Switch-mode Power Supplies can accept input voltages as low as 90V, and most computer PSUs can be switched between 120 and 230V. If you get this old 120V UPS working, it would be ideal for your PC and certain peripherals! But put a ******** big notice on the PC - SET TO 120V

 

[ericmark]

Today Tuesday 23rd August went down to check on brewing and charging and unplugged the donor battery, and this time the smart charger did not disconnect on over voltage, the voltage was dropping to 12.7 charger kicking in raising to 14.4 then charger stopping and dropping again to 12.7 volts before repeating.

The energy monitor is now recording a raise to approx 4 watt.

It seems it has just started to accept a charge.

 

[Harry Bloomfield]

I had a similar experience with my deceased partners disability scooter. Ignition left on and the two SLA's completely flat. Both of them seemed to recover eventually, by 'cheating' and charging each on smart chargers. It has been stood for a few years since then, every so often - I plug the scooter into its own charger, which immediately shows green for 'fully charged'. I've not road tested it since then, but it seems fine at tearing round the garden.

I could sell it, but second hand they don't realise much and one day it might come in, maybe.