J/30 Class Association Forums J/30 Forum The Boat, Sails and Equipment Battery selector switch

I would like to introduce myself, I am Richard Marshall and bought Detached hull 474 off e-bay last year.
Can anyone help me understand the electrical system. Shore power is fitted and works, their is a selector switch for the batteries. Does it select which battery is being charged or which is being discharged. Will their be a battery charger off the shore power. The batteries are in the locker under the sink but not in a box or secured at all. Is this normal? What is the breaker marked Blender for?
Rich

Rich - You are very fortunate if you have a breaker marked "Blender"! I would investigate that thoroughly and try multiple settings with multiple ingredients.

I do not believe the J/30 had an AC connection or battery charger as a factory option. I know many boats have them. I installed a Xantrex 10TB Battery charger. This particular model has two outputs to charge both batteries independently. It is diode isolated from the battery so does not discharge the cells when shore power is off.

The stock battery switch is a simple Off, Batt 1, Batt 2 or Both. It is manually switched. It should never be switched off when the engine is running as it will fry the alternator diodes. I usually leave it on Batt 1 on odd days and Batt 2 on even days. When the engine is run, I switch to both. Under my signature click on Projects & Documentation, then on the left menu select Rhapsody Maintenance Procedures. Check out some of the schematics and procedures I have posted there for the electrical stuff.

On Rhapsody the batteries are in a molded lip under the aft port quarter berth. They are tied down with traditional nylon webbing with buckle to tighten the webbing. Rhapsody has the old style layout. I believe your hull being newer has a different layout, so will defer to someone else that may have info on where the batteries are stored.

Thanks for the info Bill.
To clarify the switch if it is in position 1 then battery one is being used to supply DC electrics and start the engine. If the engine is running then battery 1 would be charged. Battery 2 is isolated and on stanby.
If shore power is available then both btteries should be getting charged or will that supply come through the selector switch also.
Rich

Rich - everything you say about the battery switch in the stock J/30 configuration sounds right. Regarding the effect of the switch with the battery charging - it depends on how it was wired. You'd need to check a schematic or hand-over-hand the wiring to figure it out. The charger may have been wired directly to the battery, or at the battery switch. If wired at the battery switch it could be disconnected from the battery, and the battery switch would determine what batteries were charged.

Hi Rich, welcome to the J30 world. Let me try to help clarify. Just because you have shore power, does NOT mean you have a battery charger. You would have to have a charger installed and connected to charge batteries with shore power. The batteries will be charged by the engine when it is running and the battery selector switch determines which battery is being used/charged. The batteries should be secured so they do not tip when the boat heels. Hope this helps.

I am fairly sure that their is a mains charger as one of the components in the battery locker has a sticker saying disconnect ac input before making dc connections. from the photos it just looks like a black box with no switches or lights, might be a screw in fuse on the top. It is ribbed presumably to dissipate heat.
Rich