Battery options

[rappareems]

I have a two battery set up.  Both my batteries are deep cycle, flooded batteries.  They are only three years old and need replacing.  I am considering going to dual purpose.  I leave them on board all winter which I know is probably much of the reason for their short life.  Suggestions.

Mark

[Stu Jackson]

1.  Keep them fully charged when you leave the boat and whatever batteries you get will last longer.  If you plug in all the time, beware that continued float charging is not very good for battery plates.  Newer chargers have actual "off" cycles which is good for your batteries, not your pocketbook.  If you leave them FULLY charged before winter that isn't an issue.

2.  Dual purpose have no use on a sailboat.  They were made for small but high powered go fast motorboats who have big engines, need the power to start engines which are run for short periods of time because they're so fast, and then sit and listen to music all day.  Do not go there.  Instead, since you have two deep cycles, replace them in kind with whatever technology you decide.

3.  Consider extending the life of your batteries by combining the two you have into a doubled sized house bank, and adding a separate small reserve bank.  If you're a  marina hopper this isn't necessary.  If you'd like to stay out on the hook for a night, it would help.

What makes you feel you need new ones?  Have you equalized them?  What charger do you have?

[Ken Heyman]

Whether you rescue these or buy new batteries, you may want to leave a solar panel on the boat all winter to trickle charge them. I tried this last winter (north of Chicago) and had satisfactory results. The batteries (4 six volt Trojans) survived with 12.75 volts and no evidence of a diminished capacity. Running down to the yard to charge them was unnecessary. When I developed some sciatica symptoms, a couple of years ago ,I decided to leave the batteries aboard, and sacrifice them, as opposed to my vertebrae. Both batteries and back ,currently are better off.

Ken