Considering dedicated engine start battery

[Harmonysailor]

Hi group:
We have an "84 CAL 35. Currently we have two battery banks each with 2 T105 6V @ 225Ah each. We use one for the house, one for engine starting. I'm considering adding a single 12V starting battery and wiring the T105s as a single big house battery. We run an Engle portable fridge, and chart plotter, mostly led lights. Other than a little extra weight is there a down side to the plan?

Dan Dunmire
Harmony
Stony Brook, LI NY

[rcvesselstyn]

Hi Dan, we were planning on going with the same setup, four 6 volt high amp hour batteries. We were advised against it by a battery expert who said the starting drain on the deep cycle batteries would give them a substantially shorter lifespan. We have been running just two six volt for the house and a single 12 volt high output starter battery. It has worked very well for us.

[HaroldBeer]

I think the dedicated engine start battery makes a lot of sense. While I continue to use lead-acid batteries, I'm certain that once these deep-cycle batteries need to be replaced, the next batteries will be lithium.

At that point, I'll probably install a battery-to-battery charger for the rare case that the engine battery is flat.

Harold Beer
Cal 2-27 #189
Muskegon, MI