The original battery system on Palarran consisted of a 1000 amp hour house bank, a start battery for each generator, and one for each motor
. This made no sense to me so I combined one generator and one motor
onto one start battery in the port hull
. My house bank in the starboard now starts the starboard motor and generator. So I was able to eliminate three batteries. If the house bank was low, I can start the port generator and charge it back up.
In regards to battery types, I don't believe that to be an issue. First, start batteries are usually starting big motors, not the little puppies we have in sailboats. The load just isn't the same as a car engine. And second, I have 9 batteries tied together, how much can it actually stress any single
one of them for the two seconds it takes to start.
This has worked well for me for the last two years. I also don't like the idea of separate banks because I think most people leave the selector switch set to "both" so why? Maybe some do switch them but then your cycling the batteries lower in between charges.
Kettlewells idea of having a battery booster isn't bad. They are light and cheap