We just got a new Power drive 55 trolling motor to replace the old push/pull cable one on a bass tracker boat16 foot long. The instruction seem ok until we get to the part about wiring to the battery at the back of the boat. In the booklet they want 2 AWG to run 15 feet, this has to be a misprint. the old 55 used 8 gauge and ran fine. Has anyone else come across this. the old wire is fine isn't it. 2AWG is use in welding machines. thanks for replying......jk

Too light of a wire won't do your motor any good. I'd follow what they say as crazy as it seems.

I have the same trolling motor on my boat. I ran 8 AWG and it works fine. The only issue I have noticed is, when I hit the battery condition button, it never shows more than 3/4 charge. Other than that, I've never had the battery run down before I was ready to quit fishing. Going on 7 years on my 55PD.

Always best to go with what the manufacturer recommends. They have done the studies , R&D and testing.

2 AWG is a bit beefy but not crazy. Some of your better/best quality jumper cables have that. They work WAY better than the cheaper jumper cables.

Figure out the amp draw, how long the wire will be a goggle a capacity chart.

If its a misprint or not depends on what amperage your motor says its rated for.
They should know that in high gear on the hardest day that the motor draws XXX amount of amps.
So you have to have wire to accommodate those amps you may draw, too small of wire will get hot.
The 8 awg you already have ran is rated at 40amps, throw an inline 40amp breaker on it and see how often it trips.

Hook it up using the 8awg, connect in a breaker, use a clamp meter, go test it and see how much you can make it pull and you will know how close to the limit you are.

that is AC info

it doesn't exactly fit for DC

AC you talk hundreds of feet for a needing a heavier line

DC it is more like feet

4ga is probably plenty large and you are looking around 2.20 a foot for 2ga you are looking around 3.30 a foot

if you are mounting a 800-1200 dollar trolling motor what is another 50-60 bucks to go up to the recommended wire.

also when running trolling motors , these are nice

https://marine-products.com/products/circuit-breaker-40amp

I know this doesn't exactly compute but I have a electric pot hauler that will pull up to 100 amps on full load, manufacturer says 6 ga wire for hook up, I put in a high quality marine grade 4 ga. wire and haven't any problems...#2 seems way heavy but it doesn't hurt to go heavier except to your wallet.

here is the DC wire chart https://afe.solutions/2019/09/20/dc-wire-size-charts/

looking up the 55# thrust power drive it specs 50 amp draw https://minnkota.johnsonoutdoors.co...z4VbcgQpLKuLQFp2tCLYTpsXzIIDNJE_p-uvnL4f

but when you look at the chart the chart shows wire size for amp draw with % voltage drop

so a traditional dumb trolling motor that is a motor and a power selector a 10% drop would be no big deal

but when you give it a bunch of electronics for GPS , Spot lock , built in sonar and blue tooth

was out with a guy who had a spot lock Terranova last week a BIG one he said great when it works , and he fought with it a few times to get it to lock and hold even hit a dock once as a result of it dropping.
this makes me wonder if the boat came with 6ga and is 26 feet long and then they plugged a new spot lock in that didn't exist when the boat was made if the voltage drop is enough that some times it messes with the electronics , especially in salt air his cables might be getting compromised.

makes me think about moving a battery forward
I was already thinking about moving my battery to the bow , all I need is the graph in the rear on my little fishing boat.
edit: I just have dumb trolling motors so it wouldn't care , but it saves wire and distributes weight my 14 foot johnboat gets tail heavy as it is wife has to lean forward so we can get up on plain faster then can set back down.
and I would sort of like to bump from the 15hp to a 20hp 4 stroke with a generator to charge the battery.

My batteries are toward the front, near the trolling motor. 8' length of wire at most.

From the chart ^ 8awg is good for up to 40 amps at up to 20 feet.

Looks like the first thing to know is how far and the length of wire were talking...

OP specified 15 feet

but is it 15 feet total length or as the crow flies , often with routing a battery a foot from the stern of a 16 foot boat to a connection a foot from the bow would be 14 feet but with routing 20-24 is easy depending on where things have to get routed


20 feet 40 amp draw 12v DC 8ga would look to be fine , but at 50 amps which is what the OPs model specifies , it needs to be 4ga for 20 feet if you need a 3% or less voltage drop.

Terrific folks, thanks a lot. The 2 gauge is $3.75 to 7.29 depending on the insulation - no idea what there is different insulation. We will use only the steering from the mini-pad and spot lock. We do not bass fish and don't run the motor much, more hunting for fish with the gas motor and then dropping in the electric for 10 minutes once we find them. Spot lock is one thing that we will use, the depth finder on the boat will be the only one we use. The motor comes with 10awg coming out the unit = that is what threw me off........jk OB & GCP super thanks

the 10ga is only probably 6 feet long , which works if you are connecting to a plug practically right at the battery.
for the 15-20 foot run from the back of the boat to the bow it needs heavier.


spot lock is nice , only been on one boat with it , but big time saver not dropping and pulling anchor

I agree with you and am thinking of putting the battery up forward. But it seems weird to hook 10 gauge to 2 gauge wire. Thanks....jk

it basically does the same thing as having the battery right at the end of the trolling motor 10ga wire

tiny % loss over the big wire so they can use a smaller wire on the trolling motor it's self.

They list 8awg for a 5 foot or less extension, I am going to move the battery forward and solve all the problems. Super thanks to all who helped GCP & OB especially......jk