Re: replacing starting battery
"So, to be clear using a deep cycle battery for starting is NOT going to damage it, or shorten it's life? "
How long is your piece of string?
IF the impulse load for the starter is less than the maximum impulse load the battery can supply there will be no damage. If the battery is too small, and you grind the starter too long, you'll melt the plates.
With a conventional 1.5kW or 2.5kW starter and a Group27 or Group 31 or larger battery...check with the manufacturer, there is probably no problem. You want certain? Check with the manufacturer.