There’s no denying that trolling motors have become an essential accessory for fishing and leisure boating. They help you navigate waters with precision, stealth, and ease. However, these motors are powered by specialized batteries that require regular charging to function optimally. Here lies an intriguing question – Can you charge a trolling motor battery with a car?

Can You Charge a Trolling Motor Battery with a Car?

For most boat owners, the practicality of charging their trolling motor battery with a car seems alluring. After all, it’s a solution that could save you from lugging around a separate battery charger during your boating escapades. But is this a viable and safe method?

In the simplest terms, yes, it’s technically possible to charge a trolling motor battery with a car. However, it’s not the most recommended solution due to various reasons that we will dive into in this comprehensive guide.

The Science behind Charging Batteries

Before we delve deeper into the nuts and bolts of charging a trolling motor battery with a car, it’s important to understand the basic science behind charging batteries.

What Happens When You Charge a Battery?

When you charge a battery, you’re essentially reversing the chemical reaction that happens during discharge. You’re converting electrical energy back into chemical energy stored within the battery. This process reinvigorates the battery, allowing it to power your devices again.

Types of Batteries

There are different types of batteries, each with its unique charging requirements. For instance, car batteries are typically lead-acid batteries, while trolling motor batteries might be lead-acid, AGM, or Lithium batteries. Understanding the type of battery you’re dealing with is crucial to ensure safe and efficient charging.

Drawbacks of Charging a Trolling Motor Battery with a Car

While you technically can charge a trolling motor battery with a car, it’s not always the best course of action. Here’s why:

The Risk of Overcharging

Car alternators are designed to charge car batteries, which are more robust and can handle higher charging rates. Trolling motor batteries, on the other hand, usually require a slower, more controlled charge. Therefore, charging them with a car poses a risk of overcharging, which could lead to damaging the battery, and in some cases, even cause a fire.

Disparity in Battery Types

As mentioned earlier, the type of battery can significantly impact its charging requirements. While both car and trolling motor batteries may be lead-acid, the latter often has special types like deep-cycle, AGM, or Lithium batteries. These batteries require a specific charging algorithm that a car’s alternator may not provide, leading to inefficient charging or potential damage.

Safer Alternatives to Charging a Trolling Motor Battery

If charging your trolling motor battery with a car isn’t the best solution, what options do you have? Here are some safer and more efficient alternatives:

Using a Dedicated Trolling Motor Battery Charger

These chargers are specifically designed to deliver the right amount of charge to your trolling motor battery. They monitor the battery state and adjust the charging rate accordingly to prevent overcharging.

Solar Charging

If you’re out on the water often and have access to ample sunlight, solar charging is a viable option. Solar chargers convert sunlight into electricity, providing a clean and renewable energy source for your trolling motor battery.

Also, Read: How To Remove An Outboard Motor From A Boat?


Q: Can I charge my trolling motor battery while it’s connected to the trolling motor?

A: Yes, you can, but it’s generally better to disconnect the battery before charging to prevent potential damage to the trolling motor.

Q: How often should I charge my trolling motor battery?

A: You should recharge your trolling motor battery after each use, regardless of whether it was completely discharged or not. Regular charging extends the lifespan of the battery.

Q: How long does it take to charge a trolling motor battery?

A: The charging time depends on the battery’s capacity and the charger’s output rate. As a rough estimate, it may take between 6 to 10 hours.

Q: Can I use a car battery charger to charge my trolling motor battery?

A: While technically possible, it’s not recommended. Trolling motor batteries often have different charging requirements and using a car battery charger could lead to overcharging and potential damage.

Q: What happens if I overcharge my trolling motor battery?

A: Overcharging can lead to the battery heating up, swelling, and in severe cases, it can cause the battery to burst or catch fire. It also reduces the overall lifespan of the battery.

Q: Is it safe to leave my trolling motor battery on charge?

A: With a smart battery charger designed for trolling motor batteries, it’s generally safe as these chargers have built-in systems to prevent overcharging. However, for safety, it’s best to avoid leaving the battery on charge for extended periods.


So, “Can you charge a trolling motor battery with a car?” While it’s technically possible, the potential risks to your battery and safety makes it far from the best option. Instead, consider investing in a dedicated trolling motor battery charger or exploring renewable options like solar charging. These methods ensure that your battery gets the right amount of charge it needs without the risk of overcharging or damage, allowing you to enjoy your time out on the water without worries.

Anthoni Ja
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