Axis Wakeboard Boat Forum

You shouldnt mix flooded (aka: wet cell) batteries with AGM (aka: gel) batteries. I'm not a battery expert by any means but in your case you have a flooded battery and an AGM battery. They both charge differently and discharge differently. Battery chargers are usually set up to charge either type NOT both types. So either your charger is under charging your flooded battery and fully charging your AGM battery or it could be fully charging your flooded battery and over charging your AGM. Either way...it's not good on the batteries since they charge differently. Also, the way each battery discharges or powers your accessories/amps/etc is different. That's why you should use the same types...either all flooded or all AGM. Also, you shouldn't mix sizes in the same battery bank. Example, it's ok to have a group 24 starting and two group 29 or two group 31 for stereo...but you don't want to have two different group batteries on the same bank like a group 29 and a group 31 both on stereo. There's lots of info on why you shouldn't mix battery types.

For those of you just running one battery or one stereo and one starting battery be careful. IF you deplete that battery or the one stereo battery very low AND THEN start your boat with the stereo system on, you are putting a pretty big load on your boats charging system. In this case it's best to turn your stereo off completely, run your boat at cruise or riding speed for approx 15 min to let the charging system build up the volts a little, then turn on the stereo. You can see the voltage drop or increase on your volt gauge when you turn on or off accessories/stereo.

I set mine up to be 2 isolated circuits. I have an automatic charging relay between them that will connect both together whenever a charging current is detected (i.e. the alternator is running) but automatically isolates the batteries when not charging. The battery switch is always left at battery one ( starting battery), but I can switch to 2 to start the boat of the stereo battery in a pinch.

Running an Interstate SRM-29 for my system. I have the Option 2 system in my boat and the Interstate SRM-29 works great. Huge fan on Interstate now that I have them.

I have a possibly stupid question for the guys running a starter battery and an additional one or two big deep cycles for the stereo. obviously when you're in a cove playing the music you're using the big batts but what about when you're cruising or wakeboarding/surfing and have the stereo blasting, are you on the deep cycles or the starter battery?

Both. When your engine is running, your alternator is charging batteries. The batteries are used when you are starting, or running accessories wiht the engine off. So I start on 1, run the radio (engine off) on 2, and after I start it, I switch to both.

Same here. Start with starting battery run the boat for a few minutes and switch to battery 1 and 2 on the switch. Be careful not to pass off on the switch while engine is running it can cause some big time electical issues.

Exactly, never pass through "off" position with boat running. I never use the "1" position to just start the boat like most do after floating a while. This is just personal preference and nothing wrong with starting the boat on "1" after floating a while. I just switch it to "1 + 2" position, turn the stereo off, start, get to cruise speed, and depending on voltage reading either turn on stereo or cruise 10-15 min to let voltage recover a little then turn stereo on. This way with the stereo off, the charging system does not have the heavier starting load of all the amps and speakers trying to draw from the amps. Since I'm running 4 total batteries, so far i haven't had to worry about voltage dropping to critical levels. I'm sure there may be a few guys here depleting their batteries pretty low and don't even realize it. Keep an eye on your voltage.

If you use the auto charging relay like I do, you don't have to mess with the battery switch 99% of the time. I just leave the switch on 1 all the time. I used to rely on the switch before I added that and would always forget to change it. The ARC makes things much simpler. Only cost about $100 plus maybe another $20-30 in parts to wire it in.

Thanks for mentioning that, I hadn't heard of one. Do you still have a mechanical switch?, and this is in addition to it? Or does it displace it? How do you hook it up? Found some online, but I don't see how it works from what they write.

I have the same system and am running two batteries. Dont have an onboard charger though. I usually alternate each time out between battery 1 and battery 2.