Batteries - leave on or not?

Jstew

310FV.  When I leave the dock for extended period of time (with the shore power connected) do I leave the batteries on with the charger on or do I shut them off?  Usually, it's several weeks between visits to the boat.  

youstolemybeer

i leave mine on. the battery charger will take care of them

LaRea

It's probably best to leave them on with the charger.  You want them to be fully charged at all times in case there's an emergency that needs the bilge pumps.

If any of them are conventional flooded-cell batteries, make sure you top off the water 2-3 times per season.

raybo3

I never touch my battery switches once the boat is floating. on on on

Black_Diamond

If your boat is in the water, and you have Mercury drives, the Mercathode will drain your batteries fast without a charger on. 

MarkB

Definitely with the charger on shore power leave the batteries on. There are no issues with this that I've experienced over the past 4 seasons with my Rinker. Charger keeps the batteries topped up, and the systems use the batteries as needed.

I believe the hot wired connections (engine bilge, mid berth bilge, mercathode) by-pass the switch anyhow, as they are emergency/protection systems.  I think that even if the switch is off, these systems are still powered.

Michael T

Yes, Shore Power on to keep the batteries charged or the "always on" systems could kill your batteries. There are true stories of Mercathode and other power scavenging systems killing the batteries and bilge pumps having no power resulting in boats flooding and some sinking! Shore power on.

jmichels

pretty sure when switch is off charger is still charging batteries regardless 

aero3113

jmichels said:

pretty sure when switch is off charger is still charging batteries regardless 

I thought that's how it's set up also.

JBam67

Me personally, always leave them on. Never touch them until the Fall.

raybo3

aero3113 said:

jmichels said:

pretty sure when switch is off charger is still charging batteries regardless 

I thought that's how it's set up also.

That's how it works. Charger always charges as long as the charger is on.

Michael T

100% just don't disconnect those shore power cords!

youstolemybeer

and this discussion is the exact reason why I removed that dang battery switch. I now have one dedicated start battery and one dedicated house battery..   I can now run the house battery until it is flat and not worry about what position the switch is in to start the boat