2 Bank Battery Question.

[CARIBOU]

I think I know the answer to this but I need some reassurance. I have an 89 340 Dancer twin 454,s with 1 Starting battery (not deep cycle) for Port engine, and 2 deep cycle Batteries in Parallel (12 volt double amperage ) for starboard engine start and house power. All Batteries are 27 series Interstates. Boat has OEM Pro Mariner 20 Charger. I notice periodically the port single starting battery will overflow a bit over a month or so. I check all three monthly and top off accordingly. The Sea Ray manual says the charger will bring up to charge and float. ( it is 32 year old technology so not sure about that ) With that being said, should I switch the battery switch off and leave it off so no charging will take place to the port starting battery when leaving boat for a while and only turn it on when starting engines to leave for a cruise. There is no other load on this battery other than to start the port engine. I don't want to constantly charge a starting battery correct?. This boat is all original and has the emergency start which works well in an emergency. The 2 starboard batteries have never let me down for starting or house power and never boiled over. There was never a starting battery on the starboard side just 2 deep cycle. Any input is greatly appreciated.

 

[Lazy Daze]

Most likely, the charger is on the way out - and truthfully, it's well past it's "best used by date". Eventually, it's going to completely kick the bucket and probably kill the batteries at the same time. I'd replace it NOW with a Pro Mariner ProNautic series. Check your wiring to see if it will handle it, but consider upgrading to a 30a unit.

Yes, with a proper charger, you can keep the port battery on charge all the time - in fact, with these newer chargers, it's recommended as it will increase the life of the battery.

 

[CARIBOU]

By turning off the battery switch to the port battery does it actually stop the charging power going to the battery.

 

[Lazy Daze]

No, it doesn't... unless someone rewired things at some point. You would WANT it wired to charge regardless of battery switch.

 

[CARIBOU]

Yes that makes perfect sense to me. This is our third year with the boat it's third owner. We just love the fat boats. It turns a lot of heads . Thank you for the charger info. I will inquire for sure. We are on Georgian bay in Ontario Canada hoping for a drier August. Rain rain rain.. Thanks again.

 

[Skybolt]

Those old Pro-mariner chargers only had one setting, cook the hell out of the battery. I had the same boat and same charger, switched to the newer float chargers and life was good again. One thing you might want to try is spit off the house to it's own battery. It's very easy to do on that boat. The starboard engine supply's the house, and it is a single wire coming off of the starter solenoid. You will get better performance from the batteries and they will last longer if they are not tied together. Also if you drain the house battery completely the engines still start.

 

[Pirate Lady]

These guys know more than i ever will. Mine had the original 30yo blue pro mariner when bought. Mechanic told me this thing is too hot to touch, replace it. I got a new Pro Mariner 44020 2 bank charger. Wired direct to batts. Love it. Monitors / chargers each batt separately. About $200 amazon. If you have 3 batts, get the 44029.