Defunct batteries on APC Smart UPS 1000

  • Thread starter Thread starter Brian Cryer
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Brian Cryer

I recently purchased a second hand APC Smart UPS 1000 on ebay - when it
arrived it was totally dead. (Seller gave a full no-quibble refund which was
nice.) Having done some research the most likely cause seemed to be the
batteries - if the unit thinks the batteries are dead then it won't turn on.
Taking it to work and temporarily swapping the battery with an identical
unit at work revealed this to be the case.

The replacement batteries (even non-branded ones) are not cheap, so I was
wondering whether its worth looking at either of the following two options -
or am I just wasting time (and money) and is it better to just buy new
batteries?

1. It takes two 12v sealed lead-acid batteries which are glued together
(strong glue!) so they can be handled pretty much as a single unit, but
there are two of them. I think the unit was probably left on the shelf for a
long time and has discharged (because I get the impression that it worked
the last time it was used). One of the batteries reads at 3v the other at
9v. So is it worth trying to charge these externally to the UPS to see if
they will rechange? If so how? can I use a car battery charger or do I need
something specialised?

2. Since the two batteries read 3v and 9v, is it viable/sensible to replace
the 3v one and keep the 9v one (hoping it will charge and come up to 12v)?
This would be about half the replacement cost, but I don't know whether
mixing new and old batteries like this is a good or a bad thing.

Thanks in advance.
 
I recently purchased a second hand APC Smart UPS 1000 on ebay - when it
arrived it was totally dead.
Click to expand...
1. It takes two 12v sealed lead-acid batteries which are glued together
One of the batteries reads at 3v the other at
9v. So is it worth trying to charge these externally to the UPS to see if
they will rechange? If so how? can I use a car battery charger or do I need
something specialised?
Click to expand...

If they are (sealed) lead acid batteries, you can use a normal
car battery charger. Keep away from those 'fast blasters' though.
(Those may come in handy if you need to juice a 200 Ah car
battery in 10 minutes, but they may blow your 30 Ah UPS
batteries.) Limit the charge current to say c / 10.
That makes 3 amps for a 30 Ah battery.
2. Since the two batteries read 3v and 9v, is it viable/sensible to replace
the 3v one and keep the 9v one (hoping it will charge and come up to 12v)?
Click to expand...

No. Never replace 'half a battery'. It's just a waste.
(I wouldn't even be surprised if batteries are paired in the
factory before they get glued together !)

But it doesn't hurt charging the old batteries both till 'full'
and see how they behave.
You can still replace them if they prove not to be useful.
 
Gerard Bok said:
If they are (sealed) lead acid batteries, you can use a normal
car battery charger. Keep away from those 'fast blasters' though.
(Those may come in handy if you need to juice a 200 Ah car
battery in 10 minutes, but they may blow your 30 Ah UPS
batteries.) Limit the charge current to say c / 10.
That makes 3 amps for a 30 Ah battery.


No. Never replace 'half a battery'. It's just a waste.
(I wouldn't even be surprised if batteries are paired in the
factory before they get glued together !)

But it doesn't hurt charging the old batteries both till 'full'
and see how they behave.
You can still replace them if they prove not to be useful.
Click to expand...

Thanks Gerard. I've put the batteries on charge, but they clearly aren't
charging so it looks like I'll need to buy new ones.
 
Brian said:
Thanks Gerard. I've put the batteries on charge, but they clearly aren't
charging so it looks like I'll need to buy new ones.
Click to expand...
If they are suphated(the plates), it sometimes helps,
to put a high voltage on them.
Rectify the mains, put a hetaer elements or big lamp in series with
it, and feed the battery for a few minutes, or until the series device
shows activity (lamp fully burning ot heater getting hot).
Then try again to charge.
 
Sjouke Burry said:
If they are suphated(the plates), it sometimes helps,
to put a high voltage on them.
Rectify the mains, put a hetaer elements or big lamp in series with
it, and feed the battery for a few minutes, or until the series device
shows activity (lamp fully burning ot heater getting hot).
Then try again to charge.
Click to expand...

Thank you for the suggestion. This might be the perfect solution, but its
way outside my comfort zone. (I just don't like touching the mains.)
 
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