charging house battery

[hammerhead225]

i have a friend who has 272 sailfish twin 225 has too starting batterys and one house battery he is geting no power sent to house battery the boat has shore power the dealer said it will only chage when hooked up to shore i dont belive that his radar will kill battery in half a day where is isolater located or can we put a new one in line .boat has the 3 battery switches one is just a off and on hand has the 40 amp braker for house the old owner also put a invertor on boat sorry so long any help would be good
thanks hammerhead

 

[CWOT]

I would find a different mechanic and ask him to take a look at your set-up.

If you are not good with the electrical stuff, you don't want to mess with loads or maybe fry your electronics.

 

[Fishshoreman]

It should be very easy to check and see if the house battery is charging while running the engines. Turn all switches to on. Get a multimeter and set it to DC volts. Positive probe on the positive terminal of the house batttery and common probe to negative terminal. Check voltage. Should be about 11.5-12.5. Start engines. Connect the same as discribed above and recheck. You should have over 13.2 volts while the engines are running. If you do then the engines are charging the house battery through the isolator.

I have a chase so I am not sure the isolator is installed in the same location but I am running three batteries as well with the same setup you described. My isolator is installed AFT of my fuel/water separators on the port side of the bilge bulkhead.

Hope that helps.

 

[Grog]

The battery setup doesn't sound factory. To charge the house battery you would need a voltage sensitive relay or manually parllel the house battery with one of the starting batteries. BEP makes a nice unit with disconnect switches, a parallel switch and 2 VSR's so as long as one motor is running once the charging battery is charged it will charge the house battery. Without charging, a RADAR unit can drain a battery in 1/2 a day they can suck up quite a bit of power.

 

[Curmudgeon]

Without charging, a RADAR unit can drain a battery in 1/2 a day they can suck up quite a bit of power.

I'm trying to think why run the radar off the house, since the engine(s) are likely running when it's operating ... :uhm

 

[Doc Stressor]

A simpler solution would be to get a Yamaha auxiliary charger cable (~$70) and run it from one of your engines to the house battery. You would also need to connect the negative terminal of the house battery to one of your main batteries (which should already be connected to each other with a negative lead).

That way, as soon as the battery that is controlled by the main switch position is fully charged, the house battery will get charged while you are running.

Unless batteries are maintained at close to a fully charged state, the plates will get sulfated and the battery will lose capacity faster than it should. That's a general problem with house batteries that aren't on the boat's charging circuit. You need to put them on the charger as soon as you get back or they start to go down hill after a few deep cycles.

 

[hammerhead225]

thanks for all yalls help i tell him what you all said looks like the add a battery dual ciruit system by blue sea systems will work

 

[CKJR]

Hi, That is correct, the house battery will not charge. this setup will allow the house battery to fully discharge without affecting the starting batteries. You can charge the battery by switching on the connection on to one motor. I have the same setup & what i did was to add a 2nd house battery with a/b switch so that i have 2 to run on all day, when i return to port the shore charger will top them off.