Re: UPS advice

david wrote:
On Mon, 03 Aug 2009 14:36:46 -0400, firebird-jmw rearranged some electrons
to say:

On Sat, 1 Aug 2009 17:27:24 -0700 (PDT), "flamer die.spam@xxxxxxxxxxx"
<die.spam@xxxxxxxxxxx> wrote:

On Aug 2, 2:00 am, Bob <day...@xxxxxxxxx> wrote:
On Aug 1, 1:31 am, "flamer die.s...@xxxxxxxxxxx"



<die.s...@xxxxxxxxxxx> wrote:
I have an APC smart-ups 3000 at home, which I got as a freebie from
someone who said it will need new batteries.
If you are starting with 12 volt batteries, you may be able to extend
the cables outside the unit and use car batteries at much less cost and
with much longer run time. The only trick is that the UPS may run at 24
volts with the batteries in series, so you may find it works better to
run two cables with a short series link at the batteries than to run
four cables with it going back to the box for the series jumper.

This is extremely bad advice. Do not use car batteries connected outside your UPS. The charging characteristics are different for car batteries.

Agreed, it's not optimal, but it does work. The best "alternative UPS
battery" for this would be a sealed deep-cycle battery commonly sold for
golf carts and electric boat motors.

I've used 12V 50AH sealed deep-cycle batteries (equivalent in size to a
medium car battery) ("freebies" pulled from cellsites as routine replacements) to power "freebie" UPSs quite often.


Also the charger would not be able to sense the battery temperature,which causes it to overcharge the batteries, the resulting outgassing and battery overheating can be extremely dangerous.

The APC SmartUPS 3000 *doesn't* sense temperature. UPSs that DO sense
battery temperature cost a whole lot more and are usually seen in small
datacenters.

As for outgassing, that's not a problem with a sealed deep-cycle battery.

The APC 3000 doesn't have enough current output to cause heating on
these batteries.


Stick with the batteries that are recommended.

That's easy for you to say. Do you sell replacement UPS battery "packs"?
(The APC SmartUPS 3000 uses packs made of two batteries glued together)
Can you give the OP a good price FOB New Zealand?


I've done this before. To do it with decent safety precautions,

1) Carve open the battery packs. Between the two batts, there's a jumper
wire with either a fuse or a self-resetting circuit breaker. Use those
same protectors between your substitute batteries.

2) Place the substitute batteries in a non-conductive protective container of some sort. Plastic storage bins with lids work well. Put some scrap wood or thick cardboard under the batteries as the plastic sometimes seems to weld the container to the bottom of the batteries.
Cut holes or slots to pass the cables going back to the UPS.

The end result is much longer run-time, but no improvement in maximum output. The downside is much longer recharge time if you do use the extended run-time.



.

Relevant Pages

  • Re: UPS advice
    ... someone who said it will need new batteries. ... the cables outside the unit and use car batteries at much less cost ... The only trick is that the UPS may run ... Car batteries are not designed for deep discharge, ...
    (alt.comp.hardware.pc-homebuilt)
  • Re: UPS advice
    ... If you are starting with 12 volt batteries, you may be able to extend ... run two cables with a short series link at the batteries than to run ... Do not use car batteries connected outside ...
    (alt.comp.hardware.pc-homebuilt)
  • Re: American Capitalism is like American Automobiles
    ... That little car got great mileage and ran for years with no ... Now they are claiming that SUVs were simply what the market said that it wanted - they were just responding to the market! ... Rather than use off-the-shelf lithium batteries, they are custom designing batteries for the Volt. ... I understand it can cost as much as $5,000 to replace the batteries in the hybrids that are out now, and that the batteries will only last about 5 years. ...
    (soc.retirement)
  • Re: 24v/48v Series/Parallel Switch
    ... parallel connection is a total myth. ... has limitations based on the total resistance of the circuit. ... batteries approach full charge, the current drops until at full charge ... so does the voltage drop along the cables and connections so ...
    (rec.boats.electronics)
  • Re: Almost like a slow motion civil war
    ... The squared off Town Car, the rounded off Continental, and one specialty type car would do the trick. ... For the cost of making the original membrane and then replacing it repeatedly you can buy a barge full of diesel fuel which is getting 65 MPG in the Escort in Europe. ... The problem with battery powered cars is that batteries will never be good enough to make a usable car. ... The energy cost and environmental cost of packing a huge amount of lithium ion batteries into a car is a much worse solution that a clean diesel such as VW and Mercedes already have at a reasonable cost. ...
    (rec.autos.sport.nascar)