Trolling motor battery charged by alternator?

[KeyWestBoater]

I have a Key West 1520CC with a Yamaha 70hp. I am thinking of adding a trolling motor. The dealer says I would need to use an external charger or install one for the 2nd battery. It's extra $$ to add a charger. Is it possible to have it charged by the alternator?

 

[triumphrick]

Re: Trolling motor battery charged by alternator?

Lot's of answers available if you search for similar posts. The answer seems to be no, because deep cycle trolling motor batteries require lots of charge time. Almost one hour for every two hours used. Also most good trolling motors are 24v and that means two more 12 in series which is way over what the Yammy will put out. Also, solar chargers are expensive and would need to cover most of your boat for those batteries. Good luck, and try to read the similar posts...

 

[rndn]

Re: Trolling motor battery charged by alternator?

The only way to keep the trolling motor fully charged is to use an external charger. You would need to run for hours and hours to get it fully charged with your motor. Do yourself a favor and buy an onboard charger that will also keep your starting battery fully charged for you. If you get a 24v trolling motor you will need to get 2 deep cycles and with your starting battery you would need a 3 bank charger.

 

[KeyWestBoater]

Re: Trolling motor battery charged by alternator?

My boat is 16 ft. Do you think I can use a 12v motor?

 

[CATransplant]

Re: Trolling motor battery charged by alternator?

My boat is 16 ft. Do you think I can use a 12v motor?

You can, but you won't be happy with its performance. I'm assuming you're adding a bow mount troller.

One of the most common uses of trolling motors is to hold the boat in a bit of a wind. A small 12 v one will have to run on too high a setting for good battery time.

A 24 v system is what will please you in the long run.

 

[Nandy]

Re: Trolling motor battery charged by alternator?

You can, but you won't be happy with its performance. I'm assuming you're adding a bow mount troller.

One of the most common uses of trolling motors is to hold the boat in a bit of a wind. A small 12 v one will have to run on too high a setting for good battery time.

A 24 v system is what will please you in the long run.

Hmmm, I have fished 12 v trolling motors all of my life and never had problems fishing all day in windy conditions. You must be talking about some serious winds or conditions.

To answer the OP, well, you have your answer already, you need another charger or one charger than can charge all your batteries. If you use a 12 v system you can also add the phase charger. This "charger" what it does is to connect your trolling battery to your motor only after the starting battery is fully charge. This wont fully charge your battery but it will help a bit.

 

[rndn]

Re: Trolling motor battery charged by alternator?

You can, but you won't be happy with its performance. I'm assuming you're adding a bow mount troller.

One of the most common uses of trolling motors is to hold the boat in a bit of a wind. A small 12 v one will have to run on too high a setting for good battery time.

A 24 v system is what will please you in the long run.

I too have used 12 volt trollers all of my life and have been very pleased. I have a 12 volt troller for my current 21 foot boat and the 55# moves the boat very well.

 

[Silvertip]

Re: Trolling motor battery charged by alternator?

Those recommending 24V motors for 16 foot boats would likely recommend a dually diesel to pull it down the road as well. I have a 55# Minnkota PowerDrive on an 18 foot pontoon and have no problem with power. And yes, I do use it in the wind. My 17 foot walleye boat has a 50# Power Drive and if you are standing and hit the go pedal on high speed you best be hanging onto something. Even with soft-start, you can lose your footing.

 

[Boatist]

Re: Trolling motor battery charged by alternator?

I agree with your dealer. If you have a trolling motor then you need a second battery to run the trolling motor. For a 16 foot boat 12 volts is plenty. If you use it for working a bank bass fishing 4 hours in the morning or straight trolling for trout it would work just fine. On windy days where you need to use higher power setting then your battery would be at least 50 percent discharged. You can charge it back up with your outboard and if your outboard put out 30 amps should be able to fully charge in about 12 hours.

So yes you can use the outboard with a 30 amp alternator to charge your trolling motor. 4 hours fishing and 12 hours to charge the battery.
Much cheaper to charge it at home or at the dock with a onboard charger or a smart automatic charger.

 

[KeyWestBoater]

Re: Trolling motor battery charged by alternator?

The dealer tells me 12v will be enough. He wants $1000 to install without the charger. This includes the battery. The boat already has a prewired trolling motor plug on the bow.

Any recommendations on an inexpensive one that will do the job?

Do you think this price is right or too much?

Thanks for all the feedback!

 

[Silvertip]

Re: Trolling motor battery charged by alternator?

Since the dealer has already offered you a $1000 install, didn't you ask him what that $1000 would buy? It had better be a top of the line anything. Most 55# top end trollers (Minnkota Power Drives or the MotorGuide equivalent) are can be bought for around $550. A quick release plate is $30, a large deep cycle battery is $75 to he's getting abour $350 to install this motor -- a job you can do yourself in a couple of hours. An on-board charger (single output) is about $65 and a dual output less than $100.

 

[Nandy]

Re: Trolling motor battery charged by alternator?

I dont see a reason why you cant do the job. If you are willing to pay 1k for that job please move to Charlotte and I will take care of all your aftermarket accessories installs!!! LOL!!
In a serious note, is not that hard if you are mechanical inclined. Acutally, you can use some of the money you are saving by install it yourself to buy a dual bank charger. It will same a bit of space and you will only have to deal with one AC connection. Save the existing charger for the future in case you go to 24vdc.