Trolling Motors, 40 -Minn Kota Endura Max Transom-Mount

Hey Guys

I have never owned or had much experience with trolling motors and buying batteries.

I am looking to hook up a trolling motor instead of a motor on my little boat due to weight and ease of set up. I am planning to use it as the sole and primary motor.

As of now research has led me to the Minn Kota Endura Max Transom-Mount.

Battery I am unsure of the size I will need.

AGM Deep-Cycle 240
200 CCA/32 Min @ 20 AMP

AGM Deep-Cycle 735
525 CCA/79 Min @ 10 Amp

Maybe I am way off with the type of battery I am looking at. Any input would be helpful.

You don't need agm for that. I would run a single group 31 or better yet dual group 27 lead acid batteries.

the cost difference seems to only be 40 bucks or so.

If you dont mind what is the reason one of the batteries wouldn't be suitable?

Does anybody know if the smaller battery would be enough to power the motor for say 8 hours?

In order to decide what battery to choose, you need to have 2 things figured out:
#1 how much power is your trolling motor using (amperes drained)
#2 how long do you want to run the trolling motor before recharging

Once you choose the right trolling motor for your boat, based on the boat size / weight, you look at the specs of the motor to find #1. A rule of thumb for 12V motors drain is one Ampere per each lb of thrust.

That means if you want a 30lb trolling motor, expect a drain of about 30A for each hour of trolling at full speed.

#2 is based on your needs only. Let's say you want to use it for 3 hours. That means you will burn 3 hours at a drain of 30A each hour which means 3 x 30= 90Ah. Your battery must have a capacity of at least 90Ah.

Again, this is a rule of thumb for a quick estimate. There are other factors involved, each factor making you add more battery capacity:
- decline in performance over time
- keeping a reserve as opposed to completely discharging the battery

As stated already, you don't need an AGM battery, a simple flooded battery will work fine. Costco sells decent flooded Deep Cycle batteries 115 AH for about $120.

The batteries you mentioned are too small. First one is 32 Min @ 20 AMP that means it will last you 32 minutes if your motor is draining 20Amperes and it will last only 26 minutes if your motor is draining 30Amps

Second one will last 79 Min @ 10 Amp, or about 26 minutes at 30Amps.

If you want AGM batteries, I saw some Eaton Powerware 140Ah 12V AGM for $210 + tax at Solar Shopping Mall in Mississauga. They have them on sale from time to time. Regular price for these is in the range of $300 + tax.

^^^ Good info there.
I'd get 2 batteries. Always nice to be able to get home.

The benefit of AGM is faster charging rates, in all likely hood you don't need this.

Trust me when I say you need either a single Group 31 or a dual group 27. The more time you spend fishing the more reserve capacity you want. The best deal is either Costco or a Deka battery from an independent battery retailer. The math provided is nice to read and understand, however in the real world you can't/don't want to fully discharge a battery. Nor will your battery perform the same as new over it's entire life span. My experience has taught me that bigger batteries are better, and keeping them maintained, not deeply discharging, and maintaining a proper charge is the most important for long life.

Getting back home is definitely a concern and when the trolling motor is the main propulsion system in the boat you have to know the battery state of charge at all times.

A battery monitor that will be able to keep track of all the amperes that went in and out of the battery will be a nice tool for this. You set it up once, based on the battery size and it will always show you the state of charge in Ah, or percentage.

I used a Xantrex MBX in my inflatable boat when my trolling motor was the only motor in my boat and that took the unknown out of the equation. You will always know how much charge is left in the battery and adjust your boat usage accordingly.

Thank you this is great information. I could have made a big mistake!

My group 27 from a cotsco is 110 AH i believe.

Speo. You sold me on the battery monitor for use on the battery in my inflatable until i googled it and saw the price. A little rich for my blood lol.

Just get a group 27 battery and run your 40lb all day. If you run it all full all day and never stop your not fishing.

In all reality you will fish all day even if your trolling non stop as at a troll you will not be on full thrust.

All the amp hours and amp usage listed above is darn good info. The part missing is what charger you’re using to recharge and maintain your battery. This is important and don’t cheap out. A proper and true deep cycle charger fully charges your battery and finishes the charge cycle by dropping to a half amp and increasing to over 14.2 volts. Sulfate build up is the usable acid in your battery crystallizing. This happens every time you charge your battery. At 14.2 volts and above the sulfates are broken down and become usable acid to hold a charge. This is a minute process for each charge but it actually maintains the battery acid. Pro Mariner and BPS battery chargers both do this and use a 14.4 volt and half amp maintenance cycle. Canadian tire chargers suck I my opinion don’t get one.

I used to run a 55lb trust on a 165 Princecraft all day in slop and never ran out of battery charge in my group 27.

Good luck.

Dee, I gave the Xantrex one only as an example. Xantrex XBM does a lot more than just keeping track of the battery usage, but for this application you don't really nned those functions. There are cheaper ones that just keep track of the battery state of charge in the range of $30 - $50.

Google this: "Battery Monitor DC 120v 100a Volt Current Ah Power Combo Meter Charge Discharge"

https://www.google.com/search?q=Battery+Mon...chrome&ie=UTF-8

Best batteries are AGM or Gel.
Why: because these types holds more electrical charge / kg than the regular ones. That's why are more expensive.

A good/smart charger is a must unless you want to burn money by burning batteries every year.

Do you have any proof to back up your claim? I know agm are more sensitive to over/under charging and don't like to be deeply discharged.

I've used all them, and for fishing boats I find regular lead acid to be the best bang for the buck.

Glass Matt and Gel are Sealed batteries and lead acid always have a vent for off gassing when charging.