Battery Advice

[OnTheWater]

Looking for some guidance on whether I should add a 3rd battery and if so, what the setup should look like. When we head out, we usually do some tubing/wakeboarding, but typically end up in a bay or at a beach and relax while the kids play around. Music is playing the entire time (medium volume). Sometimes, we stay overnight on the boat - kids watch a movie that is played through the stereo, so we could have lights and sound playing for a few hours. Here is my current system setup - 10'' sub 600 watts RMS, 6 Wet Sounds XS 6.5's with RBG LED, 2 Icon 8'' w/RGB LED, LED lighting in boat, 2 LifeForm6 LED underwaters, Wet Sounds RF controller, Wet Sounds BT Dual band EQ 420, Hydro Tech Amp 2x165 @ 4 ohms, Excelon amp 80*4@ 4 ohms, and Excelon 600*1 @ 2 ohms.

My thoughts are to keep my starter battery and then change out the other for an AGM deep cycle and add another AGM deep cycle and run those 2 as the house. I currently have a Battery Tender 12 Volt Power Tender Plus battery charger, but might need to change that to a dual bank charger...?

What are your recommendations?

 

[Bruce]

If you are putting in two new AGMs of the same size as house batteries then I would wire them in parallel and use a dual bank charger with one bank connected to the starter battery and a second to the house pair. If you need a faster charge you could use a triple bank charger.

But do you need three batteries? Have you run your house battery low?

I have two 31 group AGMs, one starter plus switched extra capacity for house and a house battery I have a refrigerator in my boat, play music often and do not see the need for a third battery. I use a dual bank 5A per bank charger to recharge the batteries. I have only used the starter battery for house loads a few times.

 

[OnTheWater]

Thanks @Bruce - the tower speaker, amp, and the LED speakers and lights are all new this year, so I'm not sure if I need a 3rd or not. Maybe an option would be to change the 2 current stock batteries out with something like what you have?

 

[Bruce]

Perhaps try your current battery setup for a few outings then decide if you need more?

 

[OnTheWater]

@Bruce - I might do that. I wet slip it with power, so if I needed more I guess I could increase the setup while in the slip. Here are 2 scenarios and questions - if my system drains my house battery , will it then drain my starter battery if they're both switched to on? If so, if I switch my starter to off and keep my house on, will it still drain my starter? Hope that makes sense

 

[subysti]

House battery and starter battery are separate. That's the whole point is to protect your starting battery if you kill your house battery. You can combine the 2 if needed to start your engines if the starter battery dies for some reason.

 

[Bruce]

@Bruce - I might do that. I wet slip it with power, so if I needed more I guess I could increase the setup while in the slip. Here are 2 scenarios and questions - if my system drains my house battery , will it then drain my starter battery if they're both switched to on? If so, if I switch my starter to off and keep my house on, will it still drain my starter? Hope that makes sense

Do you have one switch or two?

Traditionally the house and starter batteries and circuits are wired separately. Often the house battery can be used to start the engine but the starter battery should not run the house loads. I have not looked at the configuration in the 242.

A simple test would be to turn off your house battery and turn your starter battery on then see if you can use the stereo or other house loads. If so then the house loads can drain the starter battery. If not then you should be safe to discharge the house battery while leaving the starter battery switched on.

You could carry a jump pack you are concerned about running down both batteries while at anchor. I have been considering adding something like this to my work backpack then taking it in the boat http://www.amazon.com/Portable-Jump...1428621213&sr=8-14&keywords=lithium+jump+pack

 

[scokill]

I think if you got 3 you would definitely want an onboard charger. I have the one below and just keep it plugged in 24x7 and unplug when headed out to lake. Kept my batteries perfect over the winter. They have 3 bank.

http://www.basspro.com/Bass-Pro-Sho...attery-Charger-XPS-iT-10/10/product/10224686/

 

[Master-Spud]

Buy a couple voltage meters and see how it goes for the first bit. No point investing a bunch of extra money if you find out you never actually drag the batteries down low. If after a few outings you see you are bringing them bellow comfort range then start looking at a larger battery setup. That would be my advice, also what I am doing this year after I installed my stereo, trying 2 smaller group 24's that I already had, but if it doesn't do it, upgrade to 2x AGM 31's... if for some reason still not enough, add the 3rd battery.

 

[OnTheWater]

Thanks all! If I decide to change out my house battery for an AGM 31, do I need to change my starter battery out also to match? If so, is it an exact match or just same group or same technology? I would be adding a dual bank charger. I'm on a plane, so I can't check the batteries but I'm guessing my 242 has 2 group 24's...?

 

[Bruce]

It is fine to use different types of batteries for the house and starter batteries. Most boats do. You only need to worry about matching batteries when they are always tied together. And I understand that recent research allows for variences even then.

 

[Island Jay]

Cannot really add much here that has not been said. Basically have a starter, a back up starter if you can, and keep house separate.
Depending on the amount of AGM batteries and the group size/factory specs, you may need a bigger charger than 20 amps. Personally I would lean you toward a dry mount because the tend to perform better. Not that a waterproof XPS ( as suggested ) or prosport would not work. If you are going to start putting multiple batteries in gard parallel for a house setup, I would strongly suggest a dry mount 3 bank. Bank 1 gets house, bank 2, starter, bank 3 left open for future/backup starter. Most waterproof cannot support more than one battery per bank (Safely/effectively)

Try to keep all batteries the same kind, including the starters. If you want to connect a charger to all of them you would want them to all be the same as many chargers need them to be that way. Those that do not often have other limitations.

If I can help out here, feel free to email me.
thanks!
Jason