How To Charge A 20v Drill Battery Without Charger? 3 Methods

As any avid DIY enthusiast or professional contractor knows, a reliable drill is an indispensable tool in any toolbox. But what happens when you find yourself with a dead 20V drill battery and no charger in sight? While a dedicated charger is the recommended way to keep your drill powered up, there are alternative methods you can employ to get that battery up and running.

In this comprehensive guide, we will delve into the world of charging a 20V drill battery without a charger, exploring various methods, safety considerations, and even the science behind it. So, let’s roll up our sleeves and dive in!

Can I Charge a Drill Battery with a Laptop Charger?

The thought might have crossed your mind: can you use a laptop charger to juice up your drill battery? While it might seem like a convenient solution, there are critical factors to consider. Drill batteries come in various voltages and capacities, and not all laptop chargers are created equal. Before attempting this method, it’s crucial to check the compatibility between the laptop charger’s output specifications and the drill battery’s requirements.

However, caution is advised when considering this option. Laptop chargers may not provide the necessary current or voltage regulation, potentially leading to suboptimal charging or, worse, damage to the battery. Moreover, safety is a significant concern. Batteries can become hot during charging, and mismatched voltages could result in overheating or even fire. While it’s possible to explore this avenue, it’s paramount to prioritize safety above all.

Exploring Methods to Charge a Battery Without a Charger

Method 1: Using a Car Battery

When you find yourself in a remote location or without access to a traditional charger, your vehicle’s battery can become a viable alternative. To charge your 20V drill battery using a car battery, follow these steps:

  1. Preparation: Ensure the car is turned off, and both batteries are disconnected.
  2. Connections: Connect the positive (+) terminal of the car battery to the positive terminal of the drill battery, and do the same for the negative (-) terminals.
  3. Charging: Let the batteries sit connected for a reasonable amount of time. Monitor the temperature of the batteries to prevent overheating.
  4. Disconnect and Test: Disconnect the batteries and test the drill battery in your drill to ensure it’s adequately charged.

While this method can save the day in a pinch, it’s crucial to exercise caution. Connecting batteries incorrectly or for an extended period could lead to damage.

Method 2: Utilizing a Power Bank

A power bank, typically used for charging electronic devices like smartphones, can be repurposed to charge a 20V drill battery. Here’s how:

  1. Select a Suitable Power Bank: Look for a power bank with an output voltage close to the drill battery’s requirement.
  2. Connection: Use appropriate adapters and cables to connect the power bank’s output to the drill battery.
  3. Charging: Allow the battery to charge from the power bank. Keep an eye on the battery’s temperature to prevent overheating.

Keep in mind that power banks might not have the capacity to fully charge a drill battery, especially if it’s completely depleted. It’s a temporary solution best suited for emergencies.

Method 3: DIY Voltage Regulator Circuit

For the tech-savvy DIYers, creating a voltage regulator circuit can be a rewarding project. This method requires a good understanding of electronics and safety protocols. Here’s a simplified outline:

  1. Research and Gather Components: Study voltage regulator circuits and gather the required components, including resistors, capacitors, voltage regulators, and a PCB board.
  2. Circuit Design: Design a voltage regulator circuit that can deliver the appropriate voltage and current for your drill battery.
  3. Assembly: Assemble the components on the PCB board, following your circuit design.
  4. Connection: Connect the circuit to a power source (e.g., a higher voltage battery) and the drill battery.
  5. Monitor and Test: Monitor the output voltage and current using appropriate tools while testing the circuit’s performance.

This method offers a deeper level of customization, but it’s not recommended for beginners due to the complexity and safety risks involved.

Recharging a Dead 20V Drill Battery

The dread of a dead battery is all too familiar, but handling it properly can extend its lifespan. When dealing with a dead 20V drill battery:

  1. Avoid Deep Discharge: Prevent batteries from fully discharging whenever possible, as deep discharge can lead to irreversible damage.
  2. Storage Conditions: Store batteries in a cool, dry place away from direct sunlight and extreme temperatures.
  3. Charge Promptly: Charge a depleted battery as soon as possible to prevent further deterioration.

Determining Charging Time for a 20V Drill Battery

The charging time of a 20V drill battery varies based on factors such as capacity, charging method, and initial charge level. As a general guideline:

  • Using alternative methods might result in longer charging times compared to a dedicated charger.
  • It’s recommended to refer to the manufacturer’s recommendations for optimal charging times.

FAQs – Charging a 20V Drill Battery without a Charger

Q1: Can I charge a 20V drill battery without a charger?

A: Yes, you can charge a 20V drill battery without a charger using alternative methods such as a power adapter or a compatible device charger.

Q2: How can I charge a 20V drill battery without a charger?

A: You can charge your 20V drill battery without a charger by connecting it to a power adapter with the appropriate voltage and current specifications. Make sure the polarity matches to avoid damage.

Q3: Are there any DIY methods to charge a 20V drill battery?

A: Yes, you can create a DIY charging setup by using a bench power supply or repurposing an old laptop charger, ensuring it matches the battery’s voltage and provides a safe current.

Q4: Is solar charging possible for a 20V drill battery?

A: Yes, you can charge your 20V drill battery using solar panels and a solar charge controller. This method is environmentally friendly and ideal for remote locations.

Q5: Can I use a car battery to charge my 20V drill battery?

A: Using a car battery to charge your 20V drill battery is possible but requires a voltage regulator to prevent overcharging. It’s recommended to consult an expert before attempting this method.

Q6: Are there any risks in charging a 20V drill battery without the original charger?

A: Charging without the original charger can pose risks if voltage and current aren’t regulated properly. There’s a chance of overcharging, damaging the battery, or even causing a safety hazard.

Q7: How efficient is USB charging for a 20V drill battery?

A: USB charging can be efficient if you use a USB-to-DC converter with the correct voltage and current output. However, charging times may be longer compared to the original charger.

Q8: Can I use a laptop charger to charge my 20V drill battery?

A: Yes, you can use a laptop charger if its voltage output matches the 20V battery requirement and the current is within a safe range. Always verify polarity before connecting.

Q9: Is trickle charging a suitable method for 20V drill batteries?

A: Trickle charging can work, but it requires a specialized trickle charger to prevent overcharging. Regular monitoring is essential to avoid damaging the battery.

Q10: Are there universal chargers that work for 20V drill batteries?

A: Yes, there are universal chargers available, but ensure they are adjustable to the correct voltage and current settings for your 20V drill battery. Read reviews and check compatibility before purchasing.


While a dedicated charger is the safest and most efficient way to charge a 20V drill battery, circumstances may arise where alternatives become necessary. Exploring methods like utilizing a car battery, repurposing a power bank, or creating a voltage regulator circuit can offer temporary solutions. However, safety should always be paramount, and caution should be exercised to prevent damage to batteries or hazardous situations.

As you venture into the world of alternative charging methods, remember that understanding the compatibility between batteries, chargers, and power sources is crucial. Whether you’re in a remote location, faced with a dead battery, or simply looking to broaden your DIY skill set, these methods provide valuable insights into the world of charging a 20V drill battery without a dedicated charger. Always prioritize safety, stay informed, and keep those projects powered up!