Batteries disconnected or not

Ian

Greetings fellow boaters,

Some opinions. We have a 2003 FV310, twin 5.0 MPI, with the usual 3 batteries on board. Marina primary mechanic changed this year and his practice is to disconnect batteries at the terminal for winter (dry and shrink wrapped). The prior mechanic just switched them off at the main switches and house battery breaker and the now primary mechanic questioned this but let it go as this is what the other guy always did for years.

Thoughts - disconnect or switch off?

Thanks, Ian

aero3113

I would take the batteries home with you and keep them on a trickle charge over the winter.

MarkB

I would definitely disconnect. The switch is only as good as the wiring which if not properly done or clean could leak charge.

Michael T

Disconnect batteries. Parasitic draws that we may not be aware of can permanently damage a battery over the Winter. Most batteries discharge between 1%  and 3% per month of uncharged storage, Any battery in decent shape can survive that and be recharged in the Spring. But - a PROLONGED full discharge of most batteries (like over a 6 month lay-up) will ruin them, imo. So, again, disconnect to prevent a full discharge. Of course, having them in a warm place on a charger is best but there is no way that I can remove 5 series 31 AGMs from my cruiser every Winter.