I followed this to wire my 24 volt motor guide.Two batteries,and i am able to run 24 volts to the motor and run all my 12 volt accessories,IE;radio,bilge,livewelll,lights,cb,... ....
just run a wire from positive to negative between two batteries,now run the positive wire from motor to the positive terminal opposite the negative post you just wired.The negative lead from motor(this is the common ground)wire to the negative oppsite your first connection made.
If you don't have a fuse already installed,put in an inline fuse between powewr cable of motor and positive terminal of battery b
50 amp fuse is rfecomended
The battery with the common ground is battery A and the battery with the jumper on the negative terminal is battery B.
(jumper wire went from positive to negative)
Battery b will draw 24 volts
battery a will draw 12 and you can safely run all your gadgets and gizmos off battery a