When it comes to choosing the best trolling motor battery there are three basic types:
- AGM (absorbed glass mat) batteries
- Lead Acid Wet Cell batteries
- Lithium Iron Phosphate (LiFePO4) batteries
There are pros and cons to each type, which we explain below this panel giving our recommendations for the best product in each class.
Again, a clear first choice – the ExpertPower model is the top-selling Lithium Iron Phosphate battery on Amazon. It has a 10-year warranty, is lighter than its nearest competitor and there is no real difference in price.
The Universal Power Group battery is our clear winner here. All three products are similar in terms of performance and features, so it really comes down to price and warranty. With the cheapest price and a two-year warranty, this product stands head and shoulders above the other two.
Dakota Lithium makes Lithium Iron Phosphate batteries that are purpose built for boats and kayaks and recreational fishers. These batteries have phenomenal performance and lifespan across a range of different temperatures and uses. A clear best choice for kayak fishers prepared to spend on a battery that will last 10 years.
- Universal Power Group 12V 100Ah Trolling Motor Battery
- VMAX Charge Tank MR127 12 Volt 100Ah AGM Trolling Motor Battery
- Mighty Max Battery 12V 100Ah Trolling Motor Battery
- ExpertPower 12V 100Ah Lithium LiFePO4 Deep Cycle Rechargeable Trolling Motor Battery
- Renogy Li 12V 100Ah Smart Lithium Iron Phosphate Trolling Motor Battery
- Dakota Lithium (54Ah) Trolling Motor Battery
Trolling Motor Battery Choice Table
(based on a 12V 100Ah battery)
|Absorbed Glass Mat|
(AGM) deep cycle
|Lead Acid Wet Cell deep cycle||Lithium Iron Phosphate|
No maintenance needed
Vibration and spill resistant
Copes with frequent discharge and recharge
Average lifespan (~5 years)
|Cheap and readily available|
Copes with frequent discharge and recharge
Prone to vibration
Requires topping up
Lower lifespan (~2 years)
|More than twice as light as AGM|
Charges far faster than AGM
Copes with frequent discharge and recharge
Long lifespan (~10 years)
|Verdict||BEST CHOICE FOR COST CONSCIOUS||NOT RECOMMENDED||BEST PERFORMANCE|
Choosing A Trolling Motor Battery
Follow this procedure (we’ve assumed a 12V motor and battery combo)
1. Find Trolling Motor Specs
Determine the max amp draw (effectively the power) of your trolling motor. For an 50lb thrust motor, this is roughly 50A.
2. Decide Battery Size
Trolling motor batteries for boats
This means a 50Ah battery will run at full power for one hour before the battery is drained. In practice, most people run their trolling motor at well short of full power.
As a general rule, you want to choose a battery that could run for two hours at full speed at a minimum – so that means a 100Ah battery for a 50lb thrust (50A) motor and a 50Ah for a 25lb thrust (25A) motor.
This is the minimum capacity we’d recommend. Many experts recommend a 100Ah battery as a minimum for modern trolling motors and we’d agree to ensure you get a good day’s fishing done and have enough reserve for windy conditions.
3. Decide Battery Type
Consider the key criteria and in the table (weight, cost and features) and decide on the best battery for you.
Most people go with a AGM battery as it offers the best combination of value for money, weight and trouble free operation. Unlike wet cell batteries, they can also be installed upside down, sideways or any other configuration (as can lithium batteries).
They are also much better from a maintenance point of view that wet cell batteries as they don’t require any topping up (they are fully sealed) and don’t carry any risk of spills of acid inside your boat.
Lithium Iron Phosphate batteries are even better in terms of durability and power-to-weight ratio and would be the number one choice if money were no object, but they are expensive.
It’s worth noting those who fish in really cold conditions love these batteries as they still pump out good power in extreme cold.
Trolling Motor Battery Tips
- Never mix battery types, nor old batteries with new batteries.
- Choose the correct charger for your battery:
AGM Battery charger
Lithium Iron Phosphate battery chargers (this model also works for AGM batteries and is well priced)
- Charge batteries as soon as possible after each use – leaving batteries in a discharged state will decrease their longevity and performance.
- Check terminal connectors periodically for signs of corrosion – clean with a paste of baking soda and water.
- Store batteries in a cool, dry place in the off-season and maintain a trickle charge.
Our Best Trolling Motor Batteries – The Verdict
Selecting the correct trolling motor battery type and size is an important choice and we are confident this guide has made this much easier for.
We outlined our top picks in each class in the box at the start of this article. Here below we spell out reasons for our choices.
Best Trolling Motor Battery (AGM)
The Universal Power Group battery is our clear winner here. All three products are similar in terms of performance and features, so it really comes down to price and warranty.
With the cheapest price and a two-year warranty, this product stands head and shoulders above the other two. This battery is a really popular choice with anglers and gets great reviews. When you use it you will see why.
Best Trolling Motor Battery (Lithium Iron Phosphate)
Again, a clear first choice – the ExpertPower model is the top-selling Lithium Iron Phosphate battery on Amazon.
It has a 10-year warranty, is lighter than its nearest competitor and there is no real difference in price. This is a great option when a light weight and superior cold weather performance are important.
Best Trolling Motor Battery (Kayak)
Dakota Lithium makes Lithium Iron Phosphate batteries that are purpose built for boats and kayaks and recreational fishers.
These batteries have phenomenal performance and lifespan across a range of different temperatures and uses.
They also come with a charger. A clear best choice for kayak fishers prepared to spend on a battery that will last 10 years.
An AGM battery of the same size would be considerably cheaper, but have less than half the lifespan and the weight for the equivalent power output.
AGM Trolling Motor Batteries Reviewed:
Well priced, durable and reliable, Universal Power Group AGM batteries are a great choice for powering a trolling motor and fit in the Group 27 battery space (see here for a breakdown of dimensions for Group 27 batteries and all other types). A deserved top pick in this class.
- Sealed AGM construction is spill-free and vibration resistant
- Light battery for the power produced
- Low self discharge
- Two-year warranty
The VMAX Charge tank is a marine grade AGM battery. It is completely sealed and maintenance free and involves no contaminants.
- Fast recharge
- Sealed construction
- Fits Group 27 battery box
- One year warranty with reduced-value replacement on a sliding scale beyond one year
The Mighty Max is a popular trolling motor battery that fits a Group 27 battery box. It uses a state of the art, heavy-duty, calcium-alloy grid that provides exceptional performance and service life.
- Rechargeable spill proof battery
- High discharge rate
- Wide operating temperatures, long service life and deep discharge recover
- One-year warranty
Lithium Iron Phosphate Batteries Reviewed:
The top seller in the category on Amazon, the ExpertPower 100Ah battery has a 10-year lifetime warranty. It has a flat discharge curve holds above 12V for up to 95% of its capacity usage boosting run time over AGM batteries.
- Lightweight – 23lbs, less than half the weight of AGM equivalents
- Battery Management System (BMS) protects it from overcharge, deep discharge, overloading, overheating and short circuit
- The lithium battery’s unique built-in, and excessive low self-discharge rate ensuring up to 1 year of maintenance-free storage
The Renogy Smart Lithium Iron Phosphate Battery is lightweight and durable and has an integrated smart battery management system to prevent damage and manage the charging/discharging process.
Lightweight – 27 pounds
Long cycle life and exceptional discharge performance
Suitable for marine use
Customer service not highly rated, warranty less comprehensive than others
Dakota Lithium is a specialist manufacturer of Lithium Iron Phosphate batteries for trolling motors and other marine/fishing applications.
This battery – which is a 54Ah model versus the 100Ah models reviewed above – is an ideal trolling motor battery for kayak fishermen.
It has a class-leading 11 year warranty and performs better in cold conditions than competing batteries
- Activate battery management system to handle discharge and charge, prevent overload
- Includes charge
- Super lightweight at 16lbs
Do I need an onboard charger?
If you have a boat with onboard electrics, then yes. Onboard chargers plug into the onboard power circuit in your boat and deliver charge to your battery. The best onboard battery chargers – such as the Minn Kota Precision -work with both AGM and flooded cell batteries and can charge banks of multiple batteries.
What are all these terms and figures?
The main terms you will see mentioned in marine batteries are CCA (cold cranking amps), CA (cranking amps), AH (amp hours) and RC (reserve capacity).
As explained on the Battery Stuff website:
Cold cranking amps (CCA) is a measurement of the number of amps a battery can deliver at 0°F for 30 seconds and not drop below 7.2 volts. A high CCA battery rating is especially important in starting battery applications, and in cold weather.
CA is cranking amps measured at 32°F. This rating is also called marine cranking amps (MCA).
Reserve Capacity (RC) is the number of minutes a fully charged battery at 80°F will discharge 25 amps until the battery drops below 10.5 volts.
An amp hour (AH), as discussed above is a measure of the amount of power stored in the battery. The standard rating is an amp rating taken for 20 hours. What this means for a 100 AH rated battery is this: Draw from the battery for 20 hours, and it will provide a total of 100 amp hours. That translates to about 5 amps an hour. (5 x 20 = 100).
What about storing my AGM battery?
The best thing to while storing your AGM battery is to keep it charged. Storing an AGM battery in a discharged condition can damage it and reduce its capacity. Remember also to store batteries in a well ventilated place.
What are gel batteries?
These are similar to AGM batteries in that they are fully sealed, leak proof and spill proof. They can also be mounted in any position. Performance wise, they are fine for operating a trolling motor but they tend to be more expensive that AGM batteries and the performance advantage is not high enough to warrant the extra cost. They also require a special type of charger.
How about lithium ion batteries?
Lithium ion batteries are the best in terms of performance – they boast a superior power to weight ratio and are fast to recharge and reasonably durable. But for operating a trolling motor, which consumes a large amount of energy, it is arguably overkill to use a lithium ion battery, especially given the high cost in the capacity required. We think if you really need that high performance for light weight – such as for kayak fishermen – then lithium iron phosphate is a better bet. These batteries are cheaper and have a better safety profile than lithium iron and the best models are specially designed for marine applications.
What about different voltages?
Almost all trolling motors run on 12V power. For big boats, you can get 24V motors, but that’s rare. For these motors hooking up two 12V batteries is generally the easiest power solution.
Can’t I just buy a wet cell battery? They are much cheaper?
The answer is that you can! And they are cheaper. But with the lower upfront cost comes higher maintenance costs over the years – you need to top up the cells and cleaning the terminals relatively frequently to remove corrosion. Then there is the possibility of spills. No one wants acid sloshing around the bottom of their boat or kayak! So if you can possibly afford the upfront cost, we will always say avoid the wet cell batteries and consider a maintenance-free AGM battery instead.
How long do these batteries last?
As a general rule, count on five years for an AGM battery and 10+ for a lithium iron phosphate battery. A wet cell battery’s life is more like 2 years in this application.
How should I store my battery when it is not in use?
This will depend on your circusmtances, but best practice with AGM batteries and the other types is to charge them once you have finished your fishing session and then store in a cool dark place.
Can’t I just use a regular 12V car battery?
No! Car batteries are designed to supply high cranking power for short bursts, whereas for a trolling motor you need slow steady power output over a long period of time. You also need a battery that you can substantially deplete without it losing voltage or performance. That means a deep cycle battery. A car battery certainly doesn’t have these characteristics and will let you down if you attempt to use it to power a trolling motor.
What is a “deep cycle” battery?
A deep cycle battery is a battery that is designed to produce steady power output over an extended duration and continues to produce consistent power output through various stages of depletion. All the batteries listed here can be considered “deep cycle” batteries.
How long to charge these batteries?
That depends on the output of the charger, but generally you should think about charging AGM and wet cell batteries overnight whereas lithium ion and lithium iron phosphate batteries may be fully charged within a few hours of being connected to the charger.
What about cheap no name brand batteries?
There are cheaper battery options available than the high quality batteries listed here, but it really is a false economy looking at these options for these reasons:
Reliability – with no brand behind these batteries you can’t be sure of their quality. Boating is one of those activities where you put in a lot of time and money to get out on the water. You don’t want your trolling motor battery failing you when you do get a chance to get out and fish.
Safety – no only the safety of you and your loved ones (you certainly don’t want the trolling motor battery failing with your kids of wife on board), but also of your local waterway. Using inferior AGM batteries mean you run the risk of the casing cracking and leaking into your boat and into the water.
Durability – you need a battery that is going to last as long as the state lifetimes we give in this article for each class of battery. Hopefully it lasts longer and in many cases they will, but if you buy and cheap, inferior no name battery you are running the risk of it failing and having to be discarded after a few trips.