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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!

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 GENIUS10NOCO GENIUS5
Voltage12V12V12V12V
Current10 A10 A10 A5 A
Charger TypeOnboardOnboardPortablePortable
Dimensions LxWxH6 x 5.1 x 2.5 in8 x 11 x 10 in4.4 x 4.5 x 9.1 in4.6 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
Voltage12V x 212V x 212V x 212V x 2
Current10A per bank10A per bank6A per bank5A per bank
Charger TypeOnboardOnboardOnboardOnboard
Dimensions LxWxH7.6 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
Voltage12V x 312V x 312V x 312V x 3
Current15A per bank10A per bank10A per bank20A total
Charger TypeOnboardOnboardOnboardOnboard
Dimensions LxWxH9.25 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
Voltage12V x 412V x 412V x 412V x 4
Current15A per bank10A per bank10A per bank9A per bank
Charger TypeOnboardOnboardOnboardOnboard
Dimensions LxWxH14.38 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