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Have you ever been stranded on the water due to a dead battery

Written by Todd S. Go2marine/LFS Tech Support


 

Blue Sea Systems-Add a Battery

 

Have you every been stranded on the water due to a dead battery and only having one battery? Then you should consider adding a battery to your system. Theres nothing like being out on the water and having a dead battery when your ready to leave. By adding a battery you can dedicate a single battery for anchoring out ex: listening to the stereo, monitoring your VHF or charging your phone, and you will have a dedicated engine starting battery. This way you can enjoy the water without having to worry about a dead battery. In this step by step process we will walk you through adding a battery correctly with the blue sea systems Mini add a battery kit, along with directions on it use.

 

Supplies Needed to Keep Your Boat Battery Charged:

 

 

Steps on Setting Up A Boat Battery Charging System

 

Step 1

You’ll want to measure from the place you want to mount your switch to both batteries and that’s how much positive (red) cable you will need. The size depends on the current size in the boat. It is advisable to acquire the same size cable that is currently in the boat. Ex: 1/0 2/0 #3AWG

Battery Lugs:battery lugs

 

Step 2

The terminals on both the automatic charging relay and the battery cut of are 3/8” so you’ll need 3/8” lugs for your particular wire size. We suggest soldering the connector to the cable, it creates a solid bond that actually fuses every strand of wire together and don’t forget to heat shrink your terminals!

 

Fuse holder/fuses: You will need 3 fuse holders one for each battery and one for the automatic charging relay or (ACR).

 

Don't forget fuses

 

Step 3

 

You’ll want to start with finding a suitable location to mount your battery switch and relay. The closer to the batteries you can mount it the better. Ex: under a seat, engine compartment inboard/stern drive. Then you will want to measure the distance of needed positive cable (red) to run from each battery to your switch. So on the back of your battery switch you have four 3/8” posts, two number ones and two number twos.

 

Step 4

You will want battery one to correspond with your engine as your designated starting battery, and battery 2 to correspond with your accessories such as your stereo, GPS, fresh water pump, amp, ect. So you will wire your battery #1 positive cable to #1 on the battery switch and you will wire your positive cable coming in from your engine to the other #1 on the back of your switch. Then you need to locate which positive wire controls your accessories, that wire needs to be wired to the #2 on the back of the battery switch and then your positive cable coming from your #2 battery will wire to the other #2 on the back of the battery switch. You will want to tie your batteries together at the ground with a wire of the correct size (same size as your battery cable).

 

Step 5

 

You will have a short jumper wire (black) from the negative on battery one to the negative on battery two. When wiring up the battery switch keep in mind that you will need two positive cables coming off each battery, one will go to the battery switch and one to the ACR. The ACR allows for charging when needed. When wiring the ACR, the two other positive cables coming off your batteries will wire to each 3/8” post on the back of your relay. You will also run a smaller common ground wire to the ACR on the left hand blade terminal if looking at it from the back side.

 

What this relay allows to happen is that it automatically combines batteries during charging, isolates batteries when discharging. So if when your anchoring and it detects your accessories battery is discharging it will isolate it from the engine starting battery allowing for your engine starting battery to stay charged. Also it is sensing voltage from each battery constantly.

 

Step 6

When you get ready to store the boat for prolonged periods of time just simply move your battery switch to the off position and it kills all power to the boat.