Running out of battery power for your cordless tools on a job site or during outdoor tasks can be a major inconvenience. Fortunately, your car can be more than just transportation; it can also serve as a mobile charging station for your power tool batteries. While the original forum post humorously highlights overthinking simple solutions, the core idea of charging batteries in your car using an inverter is indeed practical and useful. This guide will expand on that concept, providing a more detailed and SEO-optimized approach for those seeking to keep their power tools running, even when far from a traditional power outlet.
Is it Possible to Charge Power Tool Batteries in Your Car?
Yes, it is absolutely possible to charge power tool batteries in your car. The key component that makes this feasible is a power inverter. A power inverter converts your car’s 12V DC power from the cigarette lighter or car battery into 120V AC power, which is the standard voltage for most power tool battery chargers. As demonstrated in the original forum post, even a basic setup with a readily available inverter can successfully charge batteries. The poster detailed using a 400W AC Delco inverter connected to their Durango’s accessory outlet to charge both Milwaukee M18 2.0Ah and 5.0Ah batteries. This real-world example shows the practicality of this method.
Alt text: AC Delco power inverter connected to a car accessory outlet.
What You Need to Charge Batteries in Your Car
To replicate this convenient charging setup, you’ll need a few essential items:
-
Power Inverter: This is the heart of your mobile charging station. Choose an inverter with enough wattage to handle your battery charger’s power draw. For most standard power tool battery chargers, a 300-watt to 400-watt inverter should be sufficient. Check the amperage rating of your charger (usually found on the charger’s label) and multiply it by 120V to determine the wattage requirement. The original post mentioned a 400W inverter, which proved adequate for a Milwaukee multi charger.
-
Power Tool Battery Charger: Use the standard charger that came with your power tool batteries. Ensure it’s compatible with the voltage output of your inverter (120V AC in North America).
-
Car with a Functional Accessory Outlet or Battery Access: Most cars have a 12V accessory outlet (cigarette lighter port). For higher wattage inverters or faster charging, connecting directly to the car battery with appropriate clamps might be necessary, but using the accessory outlet is generally simpler for charging power tool batteries.
Step-by-Step Guide to Charging Power Tool Batteries in Your Car
Follow these steps to safely and effectively charge your power tool batteries in your vehicle:
-
Start Your Vehicle (Recommended): While some inverters can operate with the car engine off, it’s generally recommended to have your engine running, especially for extended charging periods. This prevents excessive drain on your car battery, ensuring you can still start your vehicle later. As the original poster did, starting the vehicle beforehand is a good practice.
-
Connect the Power Inverter: Plug your power inverter into your car’s accessory outlet. Some inverters also come with clamps for direct battery connection if you need more power or your accessory outlet is insufficient. Ensure the inverter is securely connected.
-
Plug in Your Battery Charger: Once the inverter is powered on and providing AC power, plug your power tool battery charger into the inverter’s AC outlet, just as you would plug it into a wall socket at home.
-
Insert the Battery to Charge: Place your power tool battery into the charger. The charging process should begin as usual. Observe the charger’s indicator lights to monitor the charging progress. The original experiment noted charging times of approximately 15 minutes for a 2.0Ah battery and 75 minutes for a 5.0Ah battery, providing a realistic timeframe for in-car charging.
-
Monitor and Unplug: Keep an eye on the charging process. Once the battery is fully charged (indicated by a green light or full charge indicator on the charger), unplug the charger from the inverter, and then disconnect the inverter from your car’s accessory outlet.
Alt text: Milwaukee multi charger charging a power tool battery in a car environment.
Important Considerations and Tips
-
Battery Drain: Be mindful that running an inverter draws power from your car battery. While charging, especially with the engine running, the alternator should replenish the battery. However, prolonged charging with the engine off can drain your car battery, as highlighted by the forum poster’s anecdote about draining his truck’s battery by running the CD player all day.
-
Inverter Wattage: Choose an inverter with sufficient wattage for your charger. Overloading an inverter can damage it or prevent it from working correctly. Always check the power requirements of your charger.
-
Ventilation: Inverters can generate heat. Ensure the inverter is placed in a well-ventilated area and not covered or enclosed, especially during extended use.
-
Safety First: Always follow the safety instructions provided with your power inverter and battery charger. Do not leave the charging setup unattended for extended periods.
-
Alternative Power Sources: For more robust mobile power solutions, consider portable power stations. While inverters are convenient for occasional charging, power stations offer larger battery capacities and can power multiple devices for longer durations.
Conclusion
Charging your power tool batteries in your car is a practical solution for professionals and DIY enthusiasts who need to work remotely or on the go. By utilizing a power inverter, you can effectively turn your vehicle into a mobile charging station, ensuring your cordless tools are always ready when you need them. While seemingly a simple solution, understanding the process and necessary equipment, as detailed in this guide, ensures efficient and safe in-car battery charging. Remember to consider your power needs, choose the right inverter, and always prioritize safety while keeping your tools powered up wherever your work takes you.
