The better definitions is how long it can deliver 25 A/H maintaining a usable voltage of at least 10.5 volts.

Dennis,
And I still can't type on this Windows 8 Phone!
________________________________
From: David Beierl<mailto:dbeierl@ATTGLOBAL.NET>
Sent: ‎3/‎13/‎2013 8:35 AM
To: vanagon@GERRY.VANAGON.COM<mailto:vanagon@GERRY.VANAGON.COM>
Subject: Re: Alliance Deep Cycle? (Grp. 27) Wire To Alternator?

At 03:16 PM 3/12/2013, neil n wrote:
>The battery is rated at 25 Amps per 180 minutes. Assuming it's

Just by the way, that "Reserve Capacity" rating says it's a starting
battery.  Reserve Capacity (25 amps x so many minutes) is an
indication of how far down the road you can get after your alternator
fails, even if it damages the battery.

Yours,
David