Commander 120 Trolling Motor Battery

[Aaron Groom]

I'm getting the final rigging for my trolling motor wrapped up so I'm looking to buy a battery. My only real questions is if there are any smaller 12v batteries that will support a full day of use, or at least a morning or evening fish, so like 5-6 hours. I'm trying to keep the total weight down and maybe conserve some space, so I'd like to see if there's other option.

I'd also like to get something that's a deep cycle only. I know marine/starter batteries are not meant for prolonged deep cycle use, so I assume using it only for trolling, fish finder and some other minor accessories will cut its life down.

The trolling motor I'm using is the Minn Kota Endura 30. I know amp usage is dependent on a number of different things, but I've read that it's an 8/30; however, I have no idea what that means. I used to use the trolling motor on my 14' john boat with a standard sized marine battery (not a starter battery) and I'd get most of a day with it with only 2 people and moderate gear. The boat was also stripped down to just benches so it was incredibly light. I'd image the same battery used on my kayak would probably provide a few days of use.

I've looked around and here's some options I found:

Optima - Highly rated, but the cost is WAY too much, plus it's a dual purpose, which I think costs more than a simple deep cycle.

Cabela's AGM - Better price, and the smaller size works great, but again it's a dual purpose. 

12v Battery Pack - This looks awesome, but only 8Ah and several people recommended not to use it for a trolling motor. However, for 2 with a charger it's only $55, so run in series, this might be an option.

Ideally I'm thinking there's a happy medium between the AGM and battery packs, but I'm not finding much that's a deep-cycle only.

Any suggestions?

[Joe Corrigan]

Hey Arron,

I have a Tarpon 16 and was planning to do the same.  I would like to see some photos of how you mounted it.  I was thinking of getting the BPS small unit and perhaps trim the shaft down.  I believe the Minn Kote has that composit shaft and I don't think it can be shortened.  My plan was to go to Batteries Plus to explore options and research a solar panel to add life to the day.  Good Luck and post some photos I would like to see how you put it together.

[Aaron Groom]

I've been taking pictures of the process and plan to post the full project when I'm done. I can post some of just the trolling motor mount I made soon, but I don't expect the entire project to be completed till around June. There's a factory mount for the commander you can buy, but where's the fun in that! :)  I found a few pictures online and fabricated it from 2 layers of 1/2" polypropylene. The mount is cut out and ready to be bolted on, but I still need to come up with a steering system. I bought a half sheet (4'x4') for ~$40 and am going to use the rest to make accessories for the slidetrax system.

I'm also planning to explore some solar options for prolonged battery life as well as use it for charging when it's not in use. The problem I'm seeing though is the awkwardness of panels, so I'm hoping to find something that's semi-flexible to adhere to the sides. We'll see though. Personally I don't think I'll be able to use something with enough surface area to make any significant difference. I've also thought of trying some kind of paddle-wheel generator/alternator. This would run while trolling and I plan to do mostly river fishing, so when anchored the current would also drive it.

As for the shaft, it does seem to be made of some composite material. I would like to shorten it by about 6", but have not tried cutting it yet, though not being able to cut it has not crossed my mind. I don't think it'll be an issue. I removed the top housing, detached the switch and am going to extend the wires to the cab. But even if I can't cut it, I don't think it'll be an issue.

I came across this setup and really liked it, so I'm modeling mine after it.

[Joe Corrigan]

WOW!  Thats more than what I planed on doing.  I was just planning on making a mount that holds the motor to the side.  I have a rudder on my yak so thats not a problem.  I fish in paddle only tournaments so I want to make it extreamly portable.  Your "make it up" skills far outreach mine.  Good Luck and I do look forward to seeing it completed. 

PS.  my thoughts on the solar panel was to mount it over the top of the cargo well/rudder in the stern.  Other than my crate there is usually nothing there.  Using the Tracks I could make it easly removable.  My thought was to use it only for extended trips or long days.

[Aaron Groom]

I stopped at an All-State Battery the other day and they did have a small 12v 'utility' battery that was like 30-35mAh and it was also 100% sealed/water tight. Only downside is they wanted about $90 for it!

[Bill Lamica]

Some information for you Aaron,

The Endura 30 pound thrust uses 30 amps at full speed (#5); so say the folks at Minn Kota. Anything less than full speed 1, 2, 3 etc. will use less and may push your kayak almost as fast. Some experimenting with a hand held GPS to get your actual speed on a calm day would be a great idea to figure out what the best speed setting may be. In other words if speed #3 is 3.9 mph while setting #5 is 4.1 mph. Why use the extra Amps to go just that little bit faster?

Here's the deal with batteries: A 30Ah (amp hour) battery will power a 30 amp draw (#5 on the Endura 30) for one hour. Meaning at the end of the one hour the battery will be drawn down to a safe limit, but not dead. If you draw the battery down too far, it causes damage (sulfation) and the battery will lose efficiency and the number of times it will or can be cycle (charged, discharged and recharged). Cabela's Group 24 battery is I believe 75Ah and their Group 27 is 90ah. This means at full speed #5 on your Minn Kota the 90Ah battery will last about 3 hours.

Let's say your Endura 30 will draw 18 amps at speed #3, which by your GPS testing happens to be the best speed for your yak. The 90Ah battery would last about five hours of continuous use at speed #3 – that’s quite a bit of run time.

From my experience I find the Group 27 90ah battery lasts me a full day or more between charges with my Endura Max 40 which has the "Maximizer" circuitry (somehow helps in amperage draw). I believe it last so long because I'm not always on any one set speed. I use them all including night time trolling at speed #1. That and I paddle quite a bit to reduce noise when I’m in the stealth mode.

You are right to get a deep cycle battery. They are designed to be drawn down and recharged. A starting battery will be damaged in use as a trolling motor battery. The starting batter is not made to be cycled. Conversely a deep cycle battery is okay in a starting environment. That’s the reason Cabela's are called dual purpose; they are really a deep cycle battery, but you can use them as the outboard motor starting battery if you want to and it won’t cause any problems. But, deep cycle batteries weigh more than the typical starting battery. The AGM Group 24 weighs 54 pounds and the Group 27 weighs 63 pounds. The AGM batteries are designed in such a way they can be positioned on their side if there is not enough vertical height available, which can be of benefit in a kayak.

Another consideration - Cabela's Rechargeable 12-Volt Battery, item # IK-018049 is $25.00 without the charger. It is 8Ah and is just right for a depth sounder. Lots of people use a small battery like this in a waterproof box glued to the hull for the sounder and keep the main battery dedicated for the trolling motor. This battery cannot be laid on its side, it must stay upright.

Solar panels – The only one, so I’m told, that is small and has a built in charge controller is marketed by the battery charger people “Battery Tender” www.batterytender.com I’ve not used one yet because when you go small with solar, you don’t get much of a charge.
The Battery Tender household 120v powered 12v charger is a great charger for use with the small Cabela’s battery or you could buy the Cabela’s battery with the charger they supply. You’ll see it on the Cabela’s site.

Hey Joe… According to Minn Kota the collar that holds the composite shaft to the trolling motor head is similar to the one used on the metal shaft. The composite shaft can be shortened, but you may lose any warranty that’s left on the motor (ask Minn Kota if concerned). I’m also told to take special care when hack sawing the composite shaft. Apparently it is best to use a fine tooth blade like 20-22 teeth per inch. Second, be careful not to cut the wires. If you slip a metal tube over the wires before you cut the shaft, your blade will hit metal before it can get to the wires. Third, be careful when re-drilling the hole for the collar. Use a small drill to make a pilot hole and then go larger to make the size required.  And fourth, you’ll need to cut the wires by the same amount as the shaft in order to get everything back into the head. If you are a do-it-yourself kind of guy; do yourself a favor and watch the YouTube video on how to cut the shaft https://www.youtube.com/watch?v=QKyVKb7sGLA the video covers the stainless steel shaft, but as mentioned the collar and mounting fixture at the top is similar.

This information makes me look like some know-it-all expert… Well, not really, but I’m pretty good at research. Minn Kota, Cabela’s, Battery Tender and Batteries Plus is where I’ve gotten the information I’ve passed on in this post.