Re: replacing starting battery
First thing: switch the anchor light out to a LED. A 1-2W LED (typical anchor light) will run for days and days on a group 24 battery.
I just switched from a high CCA starter battery to using my pair of house batteries to start the engine. It works fine on my Yanmar 2GM20F. I have a small backup 3rd battery as my emergency battery should the house batteries get run all the way down. That one is never used for anything else. It's small size (U1 form factor) made it easy to fit into my 28' boat.
I'm no longer participating on SailNet.