On Fri, 18 May 2007 09:42:30 EDT, "Rick (W-A-one-R-K-T)" wrote in :

As for power supplies, you should consider a 12-volt Absorbent Glass Mat
(AGM) battery with a maintenance charger (the kind that shuts itself off
when the battery is fully charged). That will give you pretty much
whatever surge current you need, and if your power fails your station
stays up.

I strongly agree. These are a great back-up for power failures or for
field operations. I work the OKC Marathon every year, running my Yaesu
FT-857D and FT-897D from Power Battery Company 91-Ampere-Hour AGM
batteries given me when we got rid of our Muckin' Huge UPS at work.
When they're not in use, I keep them charged, so that I can run the
station during our all-too-frequent power outages. One of them will run
a Yaesu FT-*97D for about 8 hours, I've found, in my typical usage
pattern, which is listen-mostly.

Warning: these are HEAVY! Sulfuric acid and lead both are very dense.

The 91AH batteries weigh about 77 pounds each; you want them rigged
with some sort of carrying harness if you have to move them, or use
a dolly of some sort. If you're putting them on a table, shelf, or
other support, it needs to be strong enough, and if they're going in a
vehicle or trailer, they need to be secured so that side loads don't
cause them to fall.

AGM batteries are sealed, can be used indoors, and can be mounted in any
position (e.g. on their sides or even upside down, so they claim). They
are readily available (I get mine from Batteries Plus). I have a
105-amp-hour AGM battery for my motorhome, and a 33-amp-hour AGM battery
for my ARES "go kit".

There are lots of sources. Your Yellow Pages will be a great help here.

I'm told that the so-called "gel cell" batteries are actually AGM
batteries.

Seems to be the case.

--
Mike Andrews, W5EGO

Tired old sysadmin