Double--Triple--House batteries?? - Maxum Boat Owners Club

oldno7 · 07-06-2011, 01:54 PM

I have a single house battery(deep cycle), it won't make it through the night running the fridge.

What is the proper method to connect two or more house batteries and will they charge with the stock alternator or would one be better served to find a solar charging system?

dronthelake · 07-06-2011, 08:48 PM

I have a single staring battery for the port engine/generator and three deep cycle batteries wired in parallel for the starboard engine which also serve as the house batteries. I have stock alternators, a 60 AMP battery charger and a battery isolator.

The longest I have every gone without starting the generator or engines is about about 30 hours and the voltage had dropped to around 10 volts. The fridge is always on as well as a few hours of TV, DVD and DVR, a few hours of radio, several flushes of the Vacu-Flush, anchor light, various interior lights, coffee pot in the morning, microwave for popcorn (necessity with a movie), water pump (shower, toilet and dishes). I run a 1000 watt (continuous) pure sine wave inverter for the TVs/DVD/DVR & laptop charger which will not operate below 10.5 volts and a 3000 watt (continuous) modified sign wave inverter for the coffee pot, microwave and receptacles.

oldno7 · 07-07-2011, 02:19 AM

Thanks Dave, that is very helpful.

Tommyfmu · 07-08-2011, 02:15 PM

Since it sounds like you have a lot of entertainment running through your inverter, I'd suggest getting two 'golf club' 6 volt batteries wired in series and run your inverter off of that. With that setup we have never run out of inverter power, even over two full days. The 12volt items such as fridge and lights were fine running off of our house battery all night and into the next day, saving our other full battery for engine startup. The genset has its own 12 volt to start and charge all others.

biggerseagar · 07-08-2011, 05:22 PM

Since we are on the subject............I have a 2001 3000SCR. I think I have the typical set-up for how it comes out of the factory. I have two sealed starting batteries(going on 4 years) One to start the port and one to start the starboard. The isolator has to be on both for the engines to start and all the 12V stuff to work. I don't have a genny.

My question is: how can I add a third deep cycle (house battery for the frig and lights only) as a back up without going into lots of wiring stuff? Then do I need to get another charger to handle a third battery? Can I add this third battery in series or parallel to one of the two batteries for all this to work?

Roger

Tommyfmu · 07-08-2011, 06:16 PM

Roger, no expert here but I believe it can be done, but would entail disconnecting your fridge and lights from the existing 12V panel . Whether you install another 12V panel off of that third battery is up to you, otherwise your lines will have to be fused close to the battery. A separate battery switch will have to installed for that battery. More than that will depend on the configuration in place now regarding batt's and charger.