Dual Battery Setup

[Bige3345]

Dual battery setups seem to be a popular topic on the forums and I thought I’d share my setup after researching some options on the forums.

I have a 2021 SX210 with a Kicker 6 channel amp, Kicker 6.5s x 4 , and a passive 10” bazooka tube being powered.

My dual battery setup is as follows:

• OEM Interstate Group 24 battery
• NAPA Marine Group 24 Deep Cycle Battery
• BEP Distribution Cluster with DVSR
• 2x 4AWG 24-Inch Battery Inverter Cables Set, 4Gauge x 24"
• Mofeez Power Distribution Block Bus Bar, 4 x 3/8" Posts

I found this install to be very straight forward utilizing the second battery bay that already exists on the SX210. I only had to slightly modify the factory battery bay cover to make everything fit nicely. In my opinion, the busbars are a must for safety, organization, and ease of installation.

 

[HawaiiBreeze]

The dual battery set up was a must for me, so glad I did mine too.

 

[Iseoll]

I was thinking of putting a second battery in also. Having a AR210 I’m very interested in your setup. Do you have any pics of the installation? Thanks for posting the links to products you used. Was it easy to install? Thanks

 

[Bige3345]

I was thinking of putting a second battery in also. Having a AR210 I’m very interested in your setup. Do you have any pics of the installation? Thanks for posting the links to products you used. Was it easy to install? Thanks

Here are some photos. I didn’t have time do do a lot of cable management.

 

[Iseoll]

Thanks for the pics. I like your set up. I don’t have any aftermarket stereo yet, but would like to eventually. Just the peace of mind, is worth it.

 

[Favorite Mistake]

I installed a second battery last year when upgrading the sound system. Blue sea add a battery. When the boat is cruising the voltage drops to the 11s. Do y'all see this too? Is this because both batteries are inline when the engine is on? Starter battery is always 100% when tested.

 

[Farny]

I installed a second battery last year when upgrading the sound system. Blue sea add a battery. When the boat is cruising the voltage drops to the 11s. Do y'all see this too? Is this because both batteries are inline when the engine is on? Starter battery is always 100% when tested.

I usually have 13v when cruising. If your only reading 11v while the engine is running I suspect something is not right. Next outing I’ll take a look at what voltage is reading. If I get around to it I may install the second voltmeter I purchased for my house battery today.

there are some definite battery experts on here that may better be able to answer your questions - @212s, @HangOutdoors and a few others.

 

[212s]

I installed a second battery last year when upgrading the sound system. Blue sea add a battery. When the boat is cruising the voltage drops to the 11s. Do y'all see this too? Is this because both batteries are inline when the engine is on? Starter battery is always 100% when tested.

The voltage can level out due to being connected, but it shouldn't drop to 11.x unless your stereo is drawing more than the battery and charging system can produce, and your house battery is drained. Anything below 12.0v is less than 50%, 11.9v is 40%. If your house battery is getting that low, you're ruining it and you'll need to replace it soon. Deep cycle batteries should never be discharged below about 50% and recharged immediately. If you regularly use that much energy, you should consider adding a third battery to run your stereo.

 

[Bige3345]

I installed a second battery last year when upgrading the sound system. Blue sea add a battery. When the boat is cruising the voltage drops to the 11s. Do y'all see this too? Is this because both batteries are inline when the engine is on? Starter battery is always 100% when tested.

I don’t see a voltage drop. I have a volt sensing relay that prioritizes charging to the starter battery (1) when the voltage is below 13.4 v. Once the starter battery is above that it will begin to charge the house battery (2) while underway.