# Onboard alternator charger for trolling motor batteries?



## Labman1127 (Jul 27, 2012)

Does anyone have a onboard alternator charger on their boat for the purpose of re-charging their trolling motor batteries while running your big motor? 
I am considering adding a minn Kota 2 bank onboard alternator charger hooked up to my Mercury 115 outboard to charge my trolling motor batteries while running / trolling. 
Any info / tips / suggestions are appreciated.


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## DHower08 (Nov 20, 2015)

Are your batteries dieing quickly? Doing this wont substitue a nice slow charge on worn down batteries. Also unless your running miles at a time your not going to get very much charge out of an average run of the big motor


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## Labman1127 (Jul 27, 2012)

DHower08 said:


> Are your batteries dieing quickly? Doing this wont substitue a nice slow charge on worn down batteries. Also unless your running miles at a time your not going to get very much charge out of an average run of the big motor


The batteries are (2) brand new size 31 deep cycles and I am running my 80 lb terrova off them for trolling. I seem to get about 4 hours of consistant trolling use on 7 1/2 power and then the batteries die. 
I am thinking with this Onboard alternator charger, I could simply fire up my big motor and troll with that for an hour which should put enough charge back into my deep cycle batteries to use my trolling motor once again. I believe I read that up to 60% of the charging on a deep cycle marine baterery is completed within the 1st hour on charge.


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## DHower08 (Nov 20, 2015)

I believe you are correct on the 60% for one hour but i also think that is at a 20amp charge. I would think the alternator would only put out 10amp max charge although i could be wrong. You would have to break down the specs on your charging system to see if it would give enough charge to constitute the cost.


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## RJohnson442 (May 14, 2013)

the low rpm trolling isn't going to help at all. Most alternators have to hit a certain rpm to even kick on. The higher the output amperage rating on the alternator the better, but again amp output has a direct relationship with rpms.


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## tomb (Oct 9, 2004)

Staying under 6 on the Terrova will make a huge difference. Do you have a kicker?


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## Labman1127 (Jul 27, 2012)

Not yet. Kicker is the next purchase. Hoping that people start selling kickers towards the end of the fishing season. 
I am trying to find a 9.9 or 8 HP that's around 5 years old or less and in good shape (not an easy task).


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## DHower08 (Nov 20, 2015)

Get on akron canton craigslist always some good deals on 9.9 tiller and remote steer outboards


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## DHower08 (Nov 20, 2015)

Labman1127 said:


> Not yet. Kicker is the next purchase. Hoping that people start selling kickers towards the end of the fishing season.
> I am trying to find a 9.9 or 8 HP that's around 5 years old or less and in good shape (not an easy task).




https://mansfield.craigslist.org/bpo/5684107180.html


Their you go


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## Labman1127 (Jul 27, 2012)

DHower
Thanks for the lead on that motor. Looks perfect but I am ideally looking for a tiller model so I don't have to go through the expense / labor of hooking up the remote throttle & ignition. 
Thanks again


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## DHower08 (Nov 20, 2015)

No problem man. Im constantly cruising CL on my work breaks looking for stuff thats gets my attention. If i see anything ill post it up. What motor brand do you prefer


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## Labman1127 (Jul 27, 2012)

Much appreciated brother! 
Looking for ideally a Merc or Yamaha. 4 stroke, 9.9 or 8HP, Tiller, manual or electric tilt, electric or manual start. 
Ideally 2009 or newer. Thanks again for your help in the search.


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## tomb (Oct 9, 2004)

Labman1127 said:


> DHower
> Thanks for the lead on that motor. Looks perfect but I am ideally looking for a tiller model so I don't have to go through the expense / labor of hooking up the remote throttle & ignition.
> Thanks again


A good call.


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## Petermkerling (Sep 22, 2014)

The other thing to check out before you buy the minnkota alternator is if your main that you hook it up too puts out enough amps for the alternator. I ran into this problem with a older 70 evinrude and a minnkota alternator. Check to see how many amps the alternator needs vs what your main puts out. If it's short you will just burn up the alternator.


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## FishIgo (Apr 21, 2011)

I use my Terrova I Piliot in conjunction with my gas motor . I have a 40 hp Merc 4 stroke with troll control and run it as slow as it will go and finish my speed off with my Terrova. The Terrova for me must be at 4 or more so that its pulling and staying in control and it lasts all day . My trolling battery last longer than the I Piliot remote battery which I had to install a USB charger from the starting battery to charge it back up !


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