Maximum Battery distance

[prattvan]

What is the maximum distance from the outboard you can mount the battery ??

It's a 70 HP 4 stroke Suzuki

[Solarman]

Some batteries are mounted in the console, but most are in the rear compartment nearest the motor(s). The weight distribution for the boat is usually the concern. Mounted in the back of the boat, then all other loads coolers, equipment, ice (extra), additional fuel tanks can be positioned throughout the boat. Additional batteries (if needed), should be mounted where balance of boat is most needed, usually middle, or rear area.
The balance of the boat once loaded with your normal running load is very important.
Why do you ask?

[WEDOCQ]

Another important consideration is the gage of wire used. The farther from the motor, the lower the gage needs to be. Also, if you are planning on putting the batteries in the cuddy, you must use the AGM type because they do not have the same venting requirements of a regular battery.
-Shawn

[prattvan]

Thanks for the reply's, guys.

The boat is a 15/16 ft fiberglass bass boat. The motor is a DF 70. The trolling battery in located in front of the console (side console). I was considering relocating the starting battery (weighs 70lbs) towards the front/middle of the boat

[Westcoaster]

I moved the batteries in my 17' from the stern up into the cuddy, i have the DF90A on my boat, i put dual purpose AGM's in, built a box for them and secured everything down and rewired the whole boat. You need to look at your manual and see what the motor requires for cold cranking amps & amp hour storage, its good if you can figure out what your actual amp draw is during cranking ( amp meter), measure the wire length from where you want the batteries to the motor and times it by two, calculate what size wire you need using the link below, make sure you use the critical voltage drop (3%) calculation and use the chart to see what will handle your needs, i went big, its safer as you don't want that wire getting hot !

Make sure you use a good quality marine wire, tinned stranded copper !
Here is a link to help get you started.
https://www.bluesea.com/resources/1437

You can use these posts to extend your cables.

[noelm007]

there really is no maximum distance, (up to a point) as long as you have the right size battery cable, you can have the battery 50 yards away if you like.

[prattvan]

You'd be surprised how many don't follow these rules as seen in these charts.
I asked several Suzuki dealers before coming to the forum and was told 6 AWG was good enough for a battery 10 ft from the motor.

Another service manager at a Suzuki dealer said he used 4 AWG on a boat with a 200 Yamaha with the battery 12 ft from the motor.
That's 24 ft !!

[Harper]

You'd be surprised how many don't follow these rules as seen in these charts.
I asked several Suzuki dealers before coming to the forum and was told 6 AWG was good enough for a battery 10 ft from the motor.

Another service manager at a Suzuki dealer said he used 4 AWG on a boat with a 200 Yamaha with the battery 12 ft from the motor.
That's 24 ft !!

Hey...it ain't THEIR boat....why worry?