Join Date: Apr 2006
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Jim, the question is how many amps or watts or horsepower is your starter rated for? And to some extent, how readily the engine starts, i.e. with one fast crank or a bit more work.
I can tell you that I have used a 17Ah AGM battery (sold for UPSes and emergency exit lighting) to start a Volvo MD7, which should be somewhat similar. Getting down to something that small counts as abuse--but if you really want to lighten the boat and just keep it as an "emergency starting" battery, it WILL do the job.