I got a couple of old IBM brand UPSs from the 2nd hand store. They
need batteries. Would there be a problem with taking the sealed lead
acid battery out of power supply and using the garden tractor battery
all I'd need to do is use some jumpers to the battery? This would be
over the winter. The idea being it will keep the battery up over
winter, I'll have a UPS, and the TV will get some protection from power
Will it work? Any possible problems of which to be aware?
The gel cell (AGM) batteries that most likely came with the UPS are designed
for deep discharge use and can withstand pretty serious drain/charge cycles.
Your garden and car batteries are designed to provide a lot of cold cranking
amps - and then to be immediately recharged by the alternator. You will
probably kill the battery running it to depletion more than a few times.
However, the inverter in your UPS is most likely sized for the amp-hour
rating of the batteries. Exceed it, as your tractor battery is likely to
do, and you'll probably fry the inverter before you kill the battery.
So, in a word, no, it's not a good idea although I am sure a dozen people
will post after me assuring you that it's no problem. Individual results
can easily depend on the make of the UPS, the size of the battery, the type
of load, the length of time it's running, the ambient temperature, etc.
If you're using it as just a surge protector, you'll likely get away with
it. Draw some serious current through it, and all bets are off. I have
ruined one APS-brand UPS and one lawn tractor battery doing just what you're
attempting, so it's not just theoretical information. It's also why I buy
UPS batteries by the half dozen. Many will work beyond 5 years, but many
will not and I like to be on the safe side. Why have a UPS if you're going
to run it with a bad battery? Of course if all you're hooking up is a TV,
then it's no great risk.
I've been buying all my UPS batteries from a guy on Ebay called
batteryman20. Great service, good prices - no financial interest, just a
On Fri, 12 Nov 2010 17:17:05 -0500, "Robert Green"
Not true. I've got an installation with a 600va UPS running on a bank
of something like 8000 amp hours and over 50,000 cold cranking amps
for over 5 years.
Just added another 800va unit a month ago. It will be running on 2
packs of about 800 amp hours in series (24 volts) - good for about
Chances of running that battery bank flat are extremely slim, but the
cheap UPS units have not complained at all.
Not hard to ruin an APC (not aps) UPS even under normal operating
conditions. Particularly their cheap standby crap.
27 UPS units at the office - I change the batteries about every 2
years. Usually find about one bad one in 10 on the 12 volt and 24 volt
units (8ah batteries) and about the same in the 48 and 56 volt units
(6 ah batteries) - which translates to 2 or 3 badd batteries in each
of the big UPS units - one of which is designed for extended run
external battery packs (but not connected to any)
I buy mine from a local UPS distributer as well as a local battery
wholesaler - price and quality very similar - one sometimes has more
stock than the other, and one is open Saterday mornings, while the
other is not.
As you'll notice further down, I did say that invariably people will report
"no troubles." However, without knowing what's actually inside the OP's
UPS, i.e. battery capacity, fan cooling, standby v. constant on, etc. I
would be reluctant to put batteries rated for far more amp hours than what
the unit came with, especially, as Percy noted, if the design is such that
the unit runs flat before it overheats. I would think that to be especially
true of small, fanless units built to take one or two 7AH gel cells.
The units you're describing sound like very heavy duty professional units,
not that kind of consumer grade crap that APC, Belkin and some others put
out. Since I've never come across an IBM UPS and the OP didn't give us much
to go on other than it having more than one battery, I'd be reluctant to
give him the green light to power it with a source that was very much
different than the original source.
A lot depends on the usage, too. In your office setup, it's very likely
that a power failure initiates an automatic shutdown, effectively limiting
the power coming out of the UPS and thus having low potential for
overheating. I don't believe I've seen any TV's (the OP's stated load) that
will send a shutdown signal. That's the case that worries me and was the
scenario where my APC 200VA unit fried - driving a 100W lightbulb during
tests to see how long a tractor battery could power a light. Long enough to
fry the UPS, it turned out. (-"
Luck is also a factor in these sorts of setups. How far have you run them
down? I think that's where "the rubber meets the road" as they say. My APC
ran for twice the time it normally did on a tractor battery v. a gel cell,
but unfortunately by the time I smelled the burning plastic, it was toast.
It's still sitting in the salvage pile along with another inverter from
RatShack that met a similar death.
Well, at least I got the above part 1/12 right. So far. (-:
You're correct, CRS syndrome strikes again. It's APC not APS and they've
behaved themselves as long as I run them with the batteries specified by the
manufacturer. Most are single battery units (7AH) which is enough to ensure
the orderly shutdown of small home PC's. Some are even smaller. I actually
have phones, VCRs, DVRs and a bunch of other electronics running off them,
and so far, even running them to exhaustion hasn't burned one up. Based on
how hot they get when run flat, I would not be sanguine about pushing them.
They obviously have a limited duty cycle, especially the ones that are air
and not fan cooled. If I had to do it, I'd open the UPS up and stick one of
the dozens of 40 and 80mm fans I have recovered from old PCs.
I would change them more frequently, too, if someone else was paying for
I've been pushing my luck having them run for 5 years, but the Powercell
brand batteries I use have not failed earlier except for one and I have
reason to believe that it was defective from the beginning (it was an extra
in an order of 8 and I think they confused a returned unit with my order).
That's just my luck. Hey, I got a free battery. Hey, it's worthless. )-:
You probably get better prices than I do because it's cheaper to truck
palletloads of batteries to a local retailer than to have UPS ship them.
On Sat, 13 Nov 2010 01:00:54 -0500, "Robert Green"
The little one with the long service is a Best Fortress 450 or 600
if I remember correctly - it used to back up the PC at his auto
service garage untill we put in a dual conversion unit to handle the
dirty power better. The one just installed is either an APC or a
Minuteman - can't remember which and it is about 200 miles away.
The IBM used to be a rebadged APC - not sure what it is now, and which
one he has.
The one with the big battery pack is not at the office. It's at my
brother's trailer up in the backwoods around Huntsville/Parry Sound
Ontario. It runs the computer and cameras etc that make up the alarm
system as well as a few critical lights etc. and the second one will
handle some other essentials.
A 200 va APC is hardly what you call an "uninteruptible" power supply.
I call them "inturrupting" power supplies.
The system ran the PC and cammeras for over 7 days through a major
winter snow-storm outage 2 years ago - had to have been running at
least 200 hours, and the steady state load is something in excess of
200 watts. Thats 16 amps more or less, for 3200 amp hours, so just
under hald discharge on the pack.
The mail idea with a UPS on a TV is to carry through on short duration
power outages which cause the TV to loose all it's programming
settings - saved channels, time, etc. If the power goes out you are
there watching it and can power it down if the utility power does not
come back shortly
Ive used PowerCells and they are not a bad battery - but the
application at the office has the computers running 24/7 - and roughly
35% load most of the time. What killd the batteries quickest is
prolonged high temperature - and the UPS units are generally sitting
on top of the PC towers they are protecting. The big dual conversion
units are sitting in the (non fan cooled) server rack.
I do get good pricing - as a dealer and generally buying by the
carton. Last rotation was about 60 batteries.
If it is an APC (who made the unit that I burned up powering it from a
tractor battery) then I rest my case! (-:
And my opinion didn't even take into consideration the hydrogen gas that
tractor batteries give off. Great for cars and tractors running outside in
the open air. Not so good in an enclosed space. I might test the unit with
a tractor battery to ensure that the unit's not fried, but I wouldn't run an
APC UPS from a garden tractor battery because of all the gotchas that
*could* come into play. Hydrogen gas build up and a fanless inverter
running red hot? Not my cuppa tea!
On 11/12/10 04:50 pm, FatterDumber& Happier Moe wrote:
The one criticism I read of this approach is that that most UPSes don't
have fans to keep them cool: it's assumed that the battery will be flat
before the UPS has heated up much.
If your lawn-tractor battery is significantly larger than the internal
battery and the thing does switch over to battery power, the UPS
electronics could get hotter than they are designed to survive.
Also: are both batteries gel-cells? (I'm assuming that the UPS battery
is). If the lawn-tractor battery is different, it could get over- or
On Fri, 12 Nov 2010 17:18:30 -0500, "Percival P. Cassidy"
About 3/4 of my UPS units have fans. Only the low powered cheap
standby units do not.
Large battery packs need an external charger anyway - and SLA
batteries float charge at 2.25 volts per cell (13.5 volts for 12 volt)
while bulk charging is performed at up to 2.45 volts per cell (14.7
Flooded lead acid batteries are GENERALLY float charges at a slightly
lower rate - 13 to 13.2 volts, or 2.2 volts per cell (about one diode
voltage drop less than the SLA.
On Fri, 12 Nov 2010 15:50:44 -0600, FatterDumber& Happier Moe
The charging circuits in a UPS are engineered for a particular size
and type of battery. They also don't charge at a very high rate. The
best way to care for that tractor battery is to fully charge it, and
keep it COLD. Low temps slow down chemical reactions, so youry ages
slower. Once a month or so you can top up the charge. A fully charged
battery will not freeze.
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