Whats up guys. I have a question. I know many of you run deep cycle batteries to power your audio systems, amps, ect. And you obviously have a starting battery to start up the boat. How do you charge dis-similar battery types on the boat without taking them out and charging them. I have been told that you cannot charge dis-similar batteries with the same on board charging system. I am having trouble powering one amp+head unit with two starting batteries that can be charged on board at the same time. Can someone please explain the differences in how a starting battery and a deep cycle battery have to be charged when they are on the same boat. <BR> <BR>(Message edited by pyroskater00 on March 25, 2007)

Easy, change out your current starting battery to a deep cycle battery. Then just isolate your starting battery with an automatic isolator/combiner from the other bank of batteries that run your system. <BR> <BR>However, I'm not the one to ask if you can charge different batteries of different types. But I have two different types of batteries on my boat that I charge off the same charging system and I've never had a problem. This year it's time to put in all new batteries at which time I think I'll go to all deep cycles across the board.

If you go to all deep cycle batteries, how will you have enough ampage to start the boat?

Well Kraig already answered your one question w/ the isolator system. <BR> <BR>To answer your last question, Deep Cycles can have enough power to start a boat. Just depends on the battery you get. <BR> <BR>Keep in mind that if you end up draining your deep cycles low enough and keep trying to charge them with just your alt. your gonna do one of two things. Kill your alternator, or kill your battery. Even if you have an upgraded alternator, your batteries are not designed to take a constant bulk charge. <BR> <BR>Either learn to take them out, or install an onboard charger.

Mine boat came with a marine battery from the dealer. It's a deep cycle, same as an RV comes with. The extra cranking amps are necessary when the battery and/or oils are cold, or if you have a hard to start or very high compression engine. For practical purposes that means the water is frozen solid and you are using a straight weight oil. <BR>The deep cycle allows the reaction inside the battery to progress further for longer and still be reversible. On my vehicles up in Canada I get batteries with lots of cranking amps. It's not so important for a boat.