Problem with keeping batteries charged

Cab4sports

I've got a 2003 Fiesta Vee 250 that I seem to be having a problem with the batteries. The batteries are new but they seem to be going dead constantly. There is no problem with the alternator. My question is can I keep the shore power plugged in with the battery charger on the circuit breaker panel in the cabin turned on when I'm away from the boat? In my opinion this is a battery maintainer similar to a trickle charger. Someone at a marina told me that it's a fast charger and if I leave it on it will over charge (cook) my batteries - it's only designed for overnight charging. Any help would be greatly appreciated.

Black_Diamond

You should be able to keep plugged in. Do you have Merc drives?  If so, the MerCathode will drain your batteries down while in the water, as it consumes power. 

aero3113

yes, you can leave your boat plugged in with the charger. If you look up the manual for your charger it will explain how it works. Also, if your not plugged in with the charger on, your refrigerator can kill the batteries. You can turn off the refrigerator with the switch inside it if you want it off and are not using it.  

LaRea

You might need to replace the charger.  They seem to last 10-15 years.  

Any modern charger is smart enough to be always-on if you refill the water in the batteries 2-3 times a year (for flooded batteries).  

Think of it this way: if your boat springs a major leak when you're not there, the bilge pump will kill your battery and the boat will sink - unless the charger is on.  

MarkB

Yes, that's exactly the point, with shore power on, all the DC stuff that is still running and leaks to ground will be compensated via the charger. For instance your merc-cathode system will keep drawing amps, and any bilge pumps that run, from the 12V system, so the batteries will drain if you don't keep that charger on!