RE: External APC Batteries?

["Jim" <jim@xxxxxxxxxxxxxxxxx>]

Never done it (but considered it a few time), can't see there being a
problem in principle.

A few considerations.

Make sure the cables, and particularly connectors, are up to the job as
there are a lot of amps flying around!

You will need something to stop the batteries discharging into each other -
Big diodes are harder to find and not cheap.

The UPS charger is unlikely to be rated for more batteries (unless it's an
expandable unit), so an external off-line system with a big changeover
relay
to connect the extra capacity might be an option.



Jim

-----Original Message-----
From: ukha_d@xxxxxxx [mailto:ukha_d@xxxxxxx] On Behalf Of
Guy Clark
Sent: 20 December 2007 15:56
To: ukha_d@xxxxxxx
Subject: [ukha_d] External APC Batteries?

HI, Everybody!!

Speaking of UPSs and batteries....

Has anyone here had luck attaching external batteries to a UPS?   I have a
propane gas "on demand" water heater, that requires mains power
for the
on-board controller, as well as the fan and ignition system.  We live in an
area that often has power failures, particularly in the winter.

I have a spare old APC UPS that was given to me because it is relatively
old, and had bad internal batteries, not because it is broken.  My plan is
to set it up in the garage and use it to power the heater.  With some large
external batteries (like the deep-discharge batteries used in marine
applications) I'm thinking that in the event of even a couple of days of
power outage (not beyond the realm of possibility!) the UPS would allow the
heater to start up and run when needed.

I'd have to extend the battery cables to reach the external batteries, but
that's not a big problem for me.

Any comments, concerns?

Thanx for your help!!!!

Guy Clark  (in currently soggy Northern California)> To:
ukha_d@xxxxxxx> From: Wayne@xxxxxxx> Date: Thu, 20 Dec 2007
01:31:26 +0000> Subject: [ukha_d] APC Batteries.> > Hi all,> I
have a APC
SmartUPS 700 with batteries that the APC thinks needs to be > replaced.
I
have managed to get hold of a set from an APC SmartUPS 750.> > Does
anyone
know if they are compatible at all?> > They physically fit the UPS
and seem
to charge and keep the power to a > pc when I pull the mains connection.
The
only thing that seems a little > 'odd' is when I pull the power and go
onto
battery, the ups normally > beeps to let you know something not right -
which it now doesn't seem to.> > One other difference - the newer
battery
set had a connector block that > was attached to the battery red/black
spade
connectors - when they were > pulled from the 750 it has what looked
like a
'quick connector' block at > the back of the battery bay. My 700 just
has
two leads that connect to > the black/red battery terminals that
disappear
into the ups..> > There isn't any markings on the newer set of
batteries
that suggest size > or rating otherwise I could compare.> > any
ideas?> >
Cheery> Wayne.

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