Lightweight Trolling Motor Batteries

Trolling motor batteries can get heavy. If you want to keep the weight of your gear to a minimum, your battery is a good place to start.

Choosing a lightweight trolling motor battery is important for kayakers and inflatable boaters looking to cut back on the overall weight of their gear. Pontoon boat owners with more powerful motors that need 24V or 36V batteries will also benefit from lighter batteries.

The compromise?

With AGM batteries, it is power capacity. Light AGM batteries will store less energy, meaning that their Amp Hour (Ah) rating will be lower than that of larger batteries.

With lithium batteries, it is the price. They weigh 3-4 times less than similar AGM batteries, but lithium batteries cost 4-8 times more.

Let’s have a look at a few light AGM and lithium batteries.

	Battery	Description	Weight	Details
1.		AGM MIGHTY MAX ML18-12 18 Ah capacity	11.9 lbs	Details
2.		AGM VMAX V35-857 35 Ah capacity	25 lbs	Details
3.		AGM Mighty Max ML35-12 35 Ah capacity	23.15 lbs	Details
4.		Lithium Eco-Worthy Lithium-Iron Phosphate Battery 30 Ah capacity	7.2 lbs	Details
5.		Lithium Renogy Lithium-Iron Phosphate Battery 50 Ah capacity	14.77 lbs	Details
6.		Lithium Mighty Max Lithium-Iron Phosphate Batter 100 Ah capacity	30 lbs	Details

Best lightweight AGM batteries for trolling motors in 2024

AGM batteries are the number 1 choice for use with boat trolling motors. Without going into the technical working of this type of battery, suffice it to say that AGM batteries are great because they are:

• maintenance-free
• spillproof
• low self-discharge rate
• fast charging
• resistant to vibration

Here are the most popular lightweight marine batteries you can use to power your trolling motor.

Mighty Max ML18-12

This battery is super thin and light, but of course, the trade-off is that it only has an 18 Ah capacity.

If you have a light kayak and a sub-30 lB trolling motor, this battery will suffice. I would not use this with stronger motors though, as it just won’t be able to give you much time out on the water.

The opinions on Amazon customers are overwhelmingly positive, so if the low Ah is OK with you, go for it.

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VMAX V35-857 – 35 Ah

This is a very high quality battery, thus the premium in price. I have personally used this battery paired with a 40 lb thrust Minn Kota trolling motor, and got around 3 hours of boating out of it at a low-medium setting.

It always held the charge and never had any issues charging it either.

Here it is on Amazon.

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Mighty Max ML35-12 – 35 Ah

Mighty Max batteries are good quality as well. I have a friend who uses this battery with a 30 lb trolling motor, and he says it just keeps on going like the energizer bunny.

Of course, you have to watch wrist if you want to get hours of boating out of small batteries like this one.

Here it is on Amazon, check out what other people who have bought it think,

Best lightweight lithium batteries for trolling motors

If we’re going to talk about lightweight batteries for trolling motors in 2024, we need to talk about deep-cycle lithium batteries as well.

They are 3-4 times lighter than comparable lead-acid batteries. They are not widely used due to their high price, but their weight to power ratio is unbeatable for now.

Another advantage lithium marine batteries have is that they have a lifespan of around 3000-5000 cycles, while lead-based AGM batteries typically have 300-500 cycles in them.

If you use your trolling motor daily though, you will end up saving money in the long run. You would need to be a professional angler or similar for this though.

For most recreational boaters, the price of lithium batteries makes them an inhibiting factor. I have personally never used one either, and don’t know of anybody that has. The tech behind marine grade lithium batteries is new, but it is here to stay.

Let’s have a look at a few of them, so we can compare their weight and capacity to AGM batteries.

Eco-Worthy12V 35 Ah Lithium

Starting off the list is a Lithium 30 Ah battery from Eco-Worthy. Notice that a comparable AGM battery weighs 25 lbs, so almost 3x as much as this Lithium battery.

The 30 Ah Lithium Eco-Worthy battery also has a 2-year warranty, vs the 1-year warranty of AGM batteries.

Not to mention it will maintain 80% capacity after 3000 charging cycles. This brings its service life to 8x that of an AGM battery!

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Renogy Lithium-Iron Phosphate Battery – 50 Ah

The light weight and small size of this lithium battery are truly marvelous when compared to an AGM battery of the same capacity. For example, this 55 Ah AGM battery weighs 37 lbs and is 9.02 x 5.43 x 9.13 inches in size.

It is rated for 7000 cycles, while an AGM battery is rated for around 600.

The bad part? It costs 5x more than the AGM battery.

Here it is on the official Renogy site, you will get a 5% discount if you sign up for their newsletter.

In case you are interested in reading what customers have to say about this super lightweight battery, you’ll find reviews there as well.

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Mighty Max Lithium-Iron Phosphate Battery – 100 Ah

Mighty Max has entered the lithium-based deep cycle battery market. Their 100 Ah 12 v battery is incredibly light weight when compared to a similar AGM battery. A VMAX 100 Ah would weight around 70 lbs, but this battery only weighs 30.

The price is higher of course, but if you use your boat every day, it is worth it. This lithium battery has an expected life expectancy of 2500 charge cycles, compared with around 500 cycles for AGM batteries.

How long does a lightweight marine battery run a trolling motor?

How much trolling motor operating time you get out of a battery will depend on 2 things:

• the thrust of the trolling motor
• the speed setting you are using

Lightweight batteries in the 30-35 Ah range will power trolling motors up to around 35 lb of thrust. Anything stronger will have your reaching or your paddles before you can start enjoying your boat trip.

To calculate how long a battery will run a motor, let’s have a look at an average setup:

• 30 lb thrust Minn Kota trolling motor – max 30 amp draw
• 35 amp hour (Ah) AGM battery
• and a 50 Ah battery as well

The table above will give you an idea of how long a 30 lb trolling motor will run with a 35 Ah and a 50 Ah battery at various speeds.

Running the motor at full speed will draw 30 amps per hour, draining the battery in a little more than an hour.

Running the motor at half speed will draw 15 amps per hour, meaning you will get 2:20 minutes runtime.

Running the motor at the lowest speed setting will draw 5 amps per hour, so you will get 7 hours of run time.

That’s not that bad!

Ways to increase the runtime of a light trolling motor battery

AGM and Lithium marine batteries are maintenance free, but charging them properly is important in keeping them working at maximum efficiency.

First of all, read this article on how to charge your marine battery properly.

Taking care of your battery will keep its capacity at maximum throughout the life of the battery, meaning that you will get more time out on the water with each charge.

• Always keep your battery charged when not in use. Discharged batteries will sulfate, thus lower the capacity and service life of your battery.
• Get a good charger like this one. A rule of thumb is that the charger should supply power at around 10-20% of the battery’s amp-hour capacity. So for a 35 Ah battery, a 4-6 amp charger is ideal.

Battery performance is directly linked to how you use the trolling motor. This is a skill you need to learn that they don’t teach in school.

Here is how you should use the trolling motor if you want to get the most out of your battery:

• Do not run the motor at maximum thrust. This will drain the battery quickly, and will subsequently reduce the capacity of the battery by 10-15% as well.
• Run the motor at the 2-3 speed setting most of the time. This will protect your battery in the long run, and not drain it too quickly.
• Sharp speed changes will affect battery performance and cost power. You want to increase/decrease your speed gradually, instead of going from speed 1 to 5 in one twist of the wrist.

With all this said, you may need more battery capacity than what these batteries can provide. If that is the case, have a look at this list of the best deep cycle trolling motor batteries.