[rescue] Mainframe on eBay

[Phil Stracchino]

Mike Hebel wrote:
> On Sep 17, 2005, at 7:34 PM, alex at lava-net.com wrote:
>>if your ups's use 12v batteries (I've seen some crappy ones that use
>>6v) then connecting a heavy-duty car (or larger...) battery will give
>>you some really nice results.  It works best with older dummer ups's
>>as some of the newer ones seem to think there's something wrong with
>>the battery and won't power up.  I'm gonna dig up an old 1kva or >
>>unit sometime and see how long a truck battery will run my microvax...
> 
> I'd highly recommend _against_ this plan unless you have a metric 
> buttload of ventilation.
> 
> Why?  Any lead-acid battery, like an automotive one, gives off hydrogen 
> when charged.
> Not a good gas to have around electricity.


Virtually all UPSen use lead-acid cells.  It's still the best and most
cost-effective battery technology there is in terms of storing a lot of
power for a long time, then discharging it at moderate to high rates at
need.  These days, virtually all new vehicles use zero-maintenance
sealed batteries that do not vent gas when charged.  Using car or truck
batteries will work fine, so long as you hook up enough of them in
series to get the correct voltage (APC UPSen, for instance, use 24v
battery packs).


-- 
 Phil Stracchino       phil.stracchino at speakeasy.net
    Renaissance Man, Unix generalist, Perl hacker
 Mobile: 603-216-7037         Landline: 603-886-3518