Every electric trolling motor needs a battery, and every battery needs a way to charge it.
In this post we discuss two common types of trolling motor battery chargers:
- Smart/Automatic chargers
- Manual chargers.
Let’s get started!
Table of Contents
Smart/Automatic Battery Chargers
These are multi-stage, intelligent chargers, which means they monitor your battery’s current state and charge it only when necessary.
This means you can connect your smart charger to the battery and forget about the charging process. Your battery will be fully charged and properly maintained.
Even if left connected for a very long time, there is no risk of overcharging your battery.
By keeping the battery fully charged, smart chargers help prevent sulfation, which occurs when a battery is left partially charged for a longer time.
When Not to Use Smart Chargers
There are two main situations when you shouldn’t use a smart charger.
Firstly, they will not recharge a severely depleted battery with a very low voltage. Most smart charger models will not turn on to charge such a battery.
Secondly, these chargers do not perform equalization, which helps recondition the battery and prolong its life.
Still, I believe Smart or automatic chargers are the way to go if you tend to leave your battery unused for a longer time and want to see it fully charged when you want to use it again.
Manual Chargers
Manual chargers are less sophisticated and usually less expensive than smart/automatic chargers.
They don’t monitor the battery and will keep charging it until the charger is disconnected or unplugged.
This means you can’t just connect them and forget. You will need to monitor the state of the battery so it’s not overcharged. Overcharging leads to shortened battery life, damage, and potentially dangerous situations.
Two thing manual chargers are good for:
- Charging a dead or almost dead battery that has less than 5 Volts.
- Equalization charge, a controlled overcharging that helps remove sulfation and recondition the battery.
Choosing a Trolling Motor Battery Charger
Battery Type
First, you need to make sure that your charger will charge the battery you have. Most trolling motors are used with the following types of batteries:
- AGM
- Gel
- Flooded Lead Acid
- Lithium, for example: LFP or LiFePo4
If you want to use a gel or lithium-ion battery, you will need to make sure that your battery charger (and trolling motor) is compatible.
Number of Batteries
Depending on the voltage of your trolling motor, you will need to charge one or more batteries. A single battery bank charger can charge a 12-Volt battery, which is all you need if you have a 12-Volt trolling motor.
If your motor operates at 24 Volts, you will need to charge two 12 Volt batteries connected in series (double bank), at 36 Volts – three batteries (triple bank), and at 48 Volts – four (quadruple bank).
Many chargers are designed to charge multiple battery banks.
Onboard vs Portable vs DC Chargers
Onboard chargers are installed and wired permanently to the batteries. This makes them very convenient to operate as all you need to do connect them to AC power.
Portable chargers need to be connected and removed from the batteries every time you need to charge them.
DC chargers don’t require AC power. They connect to the outboard motor’s alternator and charge the batteries whenever the motor is running. The problem with this solution is that often alternators don’t generate enough current or don’t run long enough to recharge a battery fully.
Charging Current
Battery chargers come with amperage ratings that tell you how fast they can recharge depleted batteries.
The higher the Amp rating, the faster your battery will be fully charged.
Less expensive 5 Amp chargers can recharge a medium-size battery in less than 12 hours. However, if you have a large battery bank or want faster charging times, you will be much happier with a 10 Amp or 15 Amp charger.
Features
If you plan to charge your battery bank onboard or outdoor, you will need a waterproof battery charger.
Additionally, some chargers are designed to be used around salt water and come with a special corrosion-resistant coating.
Other important features to look for in a good charger are a short circuit and reverse polarity protection.
12 VOLT SMART CHARGERS – 1 BANK
NOCO Genius GEN1 1-Bank | Minn Kota Precision 1 Bank | NOCO GENIUS10 | NOCO GENIUS5 | |
Voltage | 12V | 12V | 12V | 12V |
Current | 10 A | 10 A | 10 A | 5 A |
Charger Type | Onboard | Onboard | Portable | Portable |
Dimensions LxWxH | 6 x 5.1 x 2.5 in | 8 x 11 x 10 in | 4.4 x 4.5 x 9.1 in | 4.6 x 3.4 x 8 in |
24 VOLT SMART CHARGERS – 2 BANK
Minn Kota Precision 2 Bank | NOCO Genius GEN2 | ProMariner ProSport 12A | NOCO Genius GEN5X2 | |
Voltage | 12V x 2 | 12V x 2 | 12V x 2 | 12V x 2 |
Current | 10A per bank | 10A per bank | 6A per bank | 5A per bank |
Charger Type | Onboard | Onboard | Onboard | Onboard |
Dimensions LxWxH | 7.6 x 9.3 x 3 inches | 7 x 6 x 2.5 inches | 7.25 x 2.75 x 9.9 inches | 9.15 x 7.2 x 5.39 inches |
36 VOLT SMART CHARGERS – 3 BANK
Minn Kota Precision 3 Bank | NOCO Genius GEN3 | Guest ChargePro 10/10/10 | ProMariner ProSport 20A | |
Voltage | 12V x 3 | 12V x 3 | 12V x 3 | 12V x 3 |
Current | 15A per bank | 10A per bank | 10A per bank | 20A total |
Charger Type | Onboard | Onboard | Onboard | Onboard |
Dimensions LxWxH | 9.25 x 8.25 x 3 inches | 16 x 6 x 14 inches | 9 x 4.1 x 8.7 inches | 14.5 x 6 x 8.5 inches |
48 VOLT SMART CHARGERS – 4 BANK
Minn Kota Precision 4 Bank | NOCO Genius GEN4 | Guest ChargePro 10/10/10/10 | ProMariner Protournament | |
Voltage | 12V x 4 | 12V x 4 | 12V x 4 | 12V x 4 |
Current | 15A per bank | 10A per bank | 10A per bank | 9A per bank |
Charger Type | Onboard | Onboard | Onboard | Onboard |
Dimensions LxWxH | 14.38 x 9.25 x 3 inches | 11 x 7.3 x 2.9 inches | 18 x 10 x 6 inches | 13.6 x 9.4 x 4.2 inches |