[vox-tech] UPS and auto battery

[Mark K. Kim]

I have my old "dead" UPS serving as a battery backup for my alarm clock.
Works great.  Also works for VCRs... for when there's a power outage and
you have a program set to be recorded during that time.

Don't recommend connecting car's liquid (forget which type of acid it is)
12V battery to the UPS's battery... different types of rechargeables have
different behavior and they got different circuits that work with
different types of batteries.  I don't know enough to know whether it's
safe, but I know enough to say it's not safe to do that without knowing
that it's safe.

Oh, BTW... car battery emits hydrogen gas while it's recharging.
Explosive...  I don't recommend it for indoor use.

-Mark


On Tue, 2 Mar 2004, Rod Roark wrote:

> I have had an APC Back-UPS 500 for a few years and it looks
> like the battery is finally dead.  It's a small 12V sealed
> lead-acid battery, about 6" x 2.5" x 3.5".  The back of the
> UPS says it can output 10A of current.  The battery itself
> says "12V, 7AH/20HR".
>
> One thing I never liked about this UPS is the anemic backup
> power time, about 5-10 minutes (and now zero).
>
> I guess you know where this is going... am wondering if it
> makes sense to buy a standard (sealed) car battery and wire
> it up to the UPS?  Any EE experts here care to comment?
>
> Thanks,
>
> -- Rod

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Mark K. Kim
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