Batteries

Tue May 13 13:44:52 CDT 2003

Those glass-mat batteries were original equipment in Mazda Miatas, mostly
because of their low weight, but also because they have less danger of
leaking acid when they are jostled around than a conventional one would.
The Miata has its battery bolted inside the trunk, and since the car is
capable of spirited handling, a leak resistant battery is important.

So, that means two things:

1) You should be able to order one of these otherwise hard to find fancy
batteries at any Mazda dealership.

2) If you find a Miata in the junkyard (preferably one that hasn't been
rear-end totaled), odds are the battery is one of these glass-mat ones,
it's still good, and you can pick it up cheap.

Hope that helps...

Kevin Finch
Network Administrator
DST Systems, Inc.
816/435-6039
krfinch at dstsystems.com

                      Charles Steinkuehler                                                          

                      <charles at steinkuehler        To:       kclug <kclug at kclug.org>                

                      .net>                        cc:                                              

                      Sent by:                     Subject:  Re: Batteries                          

                      owner-kclug at marauder.                                                         

                      illiana.net                                                                   

                      05/12/2003 09:36 PM                                                           

Duane Attaway wrote:
> On Mon, 12 May 2003, Hanasaki JiJi wrote:
>
>> Any recommendations on the best cost/battery life UPS's that also have
>> support for automatic shutdown via usb/parallel port interfaces?
>
> I'm an extreme kind of guy, but I usually take an old junker UPS that was
> left for dead and stick a $75 Walmart 125Ah marine battery to it.  Who
> needs an alarm for battery life when it will last all day?

Note that using marine batteries solves another common problem with the
lower-end UPS systems (including APC).  The gel-cells typically used in
these sytems do *NOT* like being fully discharged.  If you do not shut
down the UPS while the batteries still have a charge, you *WILL*
dramatically shorten their life.

The marine batteries are typically constructed for "deep discharge",
which means you can run them dry and only slightly shorten their lifespan.

Of course, for the truly power-hungry, take a page from the BattleBots
folks, and run Hawker glass-mat lead-acid cells:
http://www.hepi.com/

Their batteries can handle phenominal charge/discharge rates, and
provide better power/weight to boot (not that this matters a lot to a
UPS, but it's critical in a BattleBot!).  I'm partial to NiMH batteries
myself, but the BattleBots folks changed the rules (damn insurance
carriers!) to prohibit the high voltages I like to run (I was running 96
cell packs for 115V...enough to power line drive industrial DC servo
motors, and plenty of power with 30-50 Amp discharge rates possible), so
I guess it's back to lead-acid, fat wire (100's of amps), and big FET's
for me if I ever build another 'bot.

--
Charles Steinkuehler
charles at steinkuehler.net