Need Some Help from Experts here! Need to install Dual Batteries on 2018 AR210

[Nick Aulakh]

Guys I am looking to install two things on my boat soon :-
1. ProMariner onboard battery charger
2. Second battery for stereo. (Currently just stock stereo but in a couple months will be upgrading)

I ordered the ProMariner 2 bank charger from amazon and it arrives today https://www.amazon.com/gp/product/B00F5EBS66/ref=oh_aui_detailpage_o00_s00?ie=UTF8&psc=1

Also I have a new Group 31 AGM Deep Cycle Battery.
https://www.amazon.com/gp/product/B0042L7DZ8/ref=oh_aui_detailpage_o04_s00?ie=UTF8&psc=1

Has anyone installed these on their boat on their own? Do I need an additional battery switch? Can anyone give me an idea of how to do this? I don't think I need to connect the second battery to the motor alternator.. or do I? I can just hook both batteries with the on-board charger. Wife and I stop and listen to music for hours and my biggest fear is me draining the starter battery. So I charged my started battery fully before going out first time because it came from the dealer at 11.5Volts... so I charged it and then the voltmeter read 12.5V. But only after listening to the stock stereo for an hour with Connext switched off (stereo is separate than connext in this boat) I was at 12.0V.. which scared me. Motors start at 12V easy but does anyone know what is the minimum voltage needed to start both motors? Someone in this forum said 12V but I dont think that's correct coz motors started at 11.5V no problem when we were at the dealer.

Any tips, how to, any suggestions are so GREATLY APPRECIATED!! I bought a Yamaha after seeing this forum and the immense support structure of information you guys have for each other here!

 

[Justin Turner]

Use a dual battery switch. You can find them online or like me at Academy. I have three batteries and wired two up in parallel (positive to positive and negative to negative and it works great.

Previously I hooked the negative of my new batteries to the motor mount but that proved to be a bad ground. Easiest way for you is to hook your positive to the switch for each battery and the negative of the new battery to the negative of the existing battery. This will ensure that you have the same grounding potential for each battery.

I always switch to my dual batteries when I stop to hang out and then back to the “starter” battery when I’m ready to go cruise around. Hasn’t failed me yet

Hope that was helpful.

 

[Adrian @ JB Solutions]

Did the same as you. Second battery can be grounded to the first battery. I purchased a 2 battery switch, and battery power goes to input 2. This is as a very easy install.

 

[Nick Aulakh]

So what I am getting is that I need :-
1. A 2 battery switch.. which will replace the current on/off switch in the boat..?
2. Parallel connection of batteries with at least 4 gage wires. The length is short but heavier gage might be safer.
3. Do I need an additional fuse on the deep cycle positive terminal?
4. How do you strap your batteries? Yamaha has this cheap plastic cover on the battery but something more sturdier would be better.

Then the on-board charger just hooks on to each battery terminal. Connecting them in parallel will charge both from the motor alternator automatically. Am I wrong anywhere here?

 

[Julian]

There are three types of switches and 3 setups you will want to consider here.

1. Parallel setup. This will effectively make one big battery. You can do this with your current switch, all you'd need is 2 power cables (one red, one black) and you are all set. This setup would be charged by the engines. The down side is...if you drain the system listening to the stereo, BOTH batteries would be drained.
   
2. Separate Starter/house battery set up. In this config, each battery will have a common ground, but the + sides will be isolated. In this setup you would want another battery switch to enable you to shut off the 2nd battery. You can also buy a new switch that would allow you to turn both on at once and combine them (On/Off/Combine switch). In this setup the stereo could only drain one battery.

I prefer option 2.

You can get an ACR (automated charging relay) that would go in #2 to allow both batteries to get charged by the engines.

There is a 3rd way of wiring it....as a 1 or 2 system - effectively this has one battery connected at a time:

3. And Lastly is the option Yamaha has started installing and it uses 3 switches. This gives you the ability to only turn on what you want to turn on (I do like this setup).

 

[Nick Aulakh]

oh man that is awesome information. Thanks a lot!

Question :- For option 2, can the negative terminals of each battery be connected together?? Or I need to mount them to the engine frame??

 

[Julian]

oh man that is awesome information. Thanks a lot!

Question :- For option 2, can the negative terminals of each battery be connected together?? Or I need to mount them to the engine frame??

Yes....no matter which config you go with, you will have a common ground. Either connect them directly together, or buy a ground bus bar. I like having the ground bus bar as it results in just ONE ground wire to each battery. (yup....you can just keep buying more stuff! LOL)

You can see my bus bar almost dead center in this photo. I have too many battery switches in my boat....mainly because Yamaha was too lazy to run the amp wires over to the switches. So I asked them to fix that, and their fix was to add another switch....oh well...it works.

 

[Paul Edwards]

Hello all, loving the info provided by everyone. I’m now the owner of my first boat (2018 yamaha ar210) and looking to go with the option two that includes the ACR. I’ll be purchasing a deep cycle battery for my stereo, etc. I’m going to purchase the Blue Sea 7650.

Blue Sea Systems 7650 Add-A-Battery Kit https://www.amazon.com/dp/B000RZNP5K/ref=cm_sw_r_cp_api_1kUpBb1V9HZFN

I’ve read on some posts that the jet boats alternator isn’t adequate enough to charge a drained house battery while running. Can anyone speak to this? Also, if the alternator isn’t adequate enough to charge the house battery while running, is there a solution that doesn’t include a shore charger? I typically just putt around the lake, pull a tube, or drop anchor and listen to tunes for 3-4 hours at a time. I’ll eventually add an amp and a couple tower speakers but nothing too crazy. Any advice would be appreciated.

 

[subysti]

Look for a blue seas add a battery kit. Comes with the right switch and ACR. Will also show you how to do all the wiring.

 

[Beachbummer]

There is a third option that gives you isolation without an ACR.

Dedicated off/1/2/1+2 switch.

Better than big battery, but you need to manage switching to make sure you are on the right battery/switch position according to your use.

Big advantage over permanent connection is that you can be saved from a dead battery by switching to the other battery and getting home.

It requires more management, but it's cheaper and simpler. I would strongly suggest this over parallel connection with your existing switch.


Something like this
https://express.google.com/u/0/prod...t=eid-lsjeuxoeqt,4181971&utm_campaign=8175035

 

[tdonoughue]

@Paul Edwards , yes, the link you have is to the Add-A-Battery Kit that was referenced. It includes a switch and an ACR. It is the one I have. Good kit.

To your question on the alternator: technically, our boats do not have one. On the parts diagrams they call it a 'generator'--technically it is a magneto (like you would find on a lawnmower engine). It *will* charge the batteries, just very, very slowly. Basically, it provides electricity enough to run the spark plugs plus a little extra.

It sounds like your use profile is about like mine. Check my sig block for my equipment at this point. I have shore power I hook into regularly overnight on a trickle charger. However, 1x year or so I go out with the boys for a weekend of lake study (actually, it is next weekend). Again, use profile similar to yours, only for 2.5 to 3 days (without charging). Never run out of battery yet (knock on wood) to the point where I needed to even combine them.

So, if you can add a charger to charge while you are away (e.g. during the week), I think you will basically be fine all weekend with what you have/plan.