Do Boat Batteries Charge Themselves. Yes a deep cycle battery can be used to start your motor in a pinch but a two- or three-battery system is highly recommended to separate the engine battery from the accessory house batteries. Yes batteries will discharge at a rate of anywhere from 2-5 per month just sitting on a shelf.
Using a faulty charger. Most chargers that were designed to charge you car batteries were not designed to charge your boat batteries. Almost all electric start outboards have an alternator to recharge the battery.
A sealed leadacid or AGM at 144 volts.
As a load is placed on them and also as they are discharged the voltage will drop. Make sure you dont join the two leads to one and other. That considerably enhances the risk of the battery exploding due to an arc between the plates inside the battery. For one thing many chargers -- especially the less-expensive ones -- dont always completely shut down.
