The discussion #1 and #2 Batteries (from 03/2021) revolves around the best configuration for batteries on a sailboat. Bill Prange is considering replacing his old #2 battery with a dedicated deep cycle starting battery, and is weighing the pros and cons of retaining two Dual Purpose batteries versus one Dual Purpose and one dedicated starting battery.
Elizabeth Powers suggests ditching Dual Purpose batteries in favor of deep cycle batteries, which can start the engine and last longer. She recommends alternating between batteries to ensure regular cycling and upgrading battery cables to reduce voltage drop.
Joe Valinoti notes that having two identical batteries can mask issues with bad batteries, and suggests installing the same size or spec’d pump.
In a follow-up post, Bill Prange mentions that his marine electrician updated his charging system two years ago, allowing both batteries to be charged on shore power and by the alternator, with the #1 battery being charged first. This update has made a significant difference in his experience.