How To Test Laptop Battery With Multimeter

Maintaining your laptop battery’s health is crucial for ensuring your device’s longevity and reliability. A multimeter is one of the most effective ways to assess your battery’s condition.

This comprehensive guide will walk you through testing your laptop battery with a multimeter. This step-by-step tutorial is designed for beginners and experienced users, ensuring you can easily follow along and accurately diagnose your battery’s health.

Why Test Your Laptop Battery?

Laptop batteries degrade over time, leading to reduced performance, shorter battery life, and unexpected shutdowns. Regularly testing your battery helps you:

  • Identify issues early: Detect problems before they become severe.
  • Maintain performance: Ensure your laptop runs smoothly without interruptions.
  • Extend battery life: Take preventative measures to prolong the battery’s lifespan.

How To Test Laptop Battery With Multimeter

Tools You’ll Need

Before we begin, gather the following tools:

  • Multimeter: A device that measures voltage, current, and resistance.
  • Screwdriver: Open your laptop and access the battery (if it’s not removable).
  • Safety gear: Gloves and eye protection for safety.

Step 1: Prepare Your Laptop

  1. Shut down your laptop: Ensure your laptop is completely turned off to avoid electrical hazards.
  2. Unplug the charger: Disconnect your laptop from any power source.
  3. Access the battery: Depending on your laptop model, you may need to remove the back panel using a screwdriver to access the battery.
remove laptop battery

Step 2: Set Up the Multimeter

  1. Turn on the multimeter and set it to the DC voltage setting, typically represented by a “V” with a straight line.
  2. Choose the correct voltage range: Select a range that covers your laptop battery’s voltage. For most laptop batteries, a range of 20V is suitable.

Step 3: Measure the Battery Voltage

  1. Identify the battery terminals: Locate the positive (+) and negative (-) terminals on the battery.
  2. Place the probes: Touch the multimeter’s red probe to the positive terminal and the black probe to the negative terminal.
  3. Read the voltage: Check the multimeter’s display for the voltage reading. A healthy laptop battery reads close to its rated voltage (e.g., 10.8V, 11.1V, 14.8V, or 15V).

Step 4: Interpret the Results

  • Healthy Battery: If the voltage reading is close to the rated voltage, your battery is in good condition.
  • Low Voltage: A significantly lower voltage indicates a weak or degraded battery that may need replacement.
  • No Voltage: If the multimeter shows no voltage, the battery might be dead or there could be a connection issue.

Step 5: Additional Testing (Optional)

For a more thorough assessment, you can perform a load test:

  1. Reconnect the battery: Place it back into the laptop if it is removed.
  2. Turn on the laptop: Power on the device and let it boot up.
  3. Measure the voltage again: With the laptop running, measure the voltage at the battery terminals. A significant drop in voltage under load indicates a weak battery.
low laptop battery

Safety Precautions on Testing a Laptop Battery With Multimeters

Testing a laptop battery with a multimeter involves handling electrical components, which can be hazardous if not done correctly. Here are detailed safety precautions to ensure a safe and effective testing process:

Avoid Short-Circuiting

  1. Isolate the Probes: Never let the multimeter probes touch each other while connected to the battery terminals. This can cause a short circuit, sparks, battery damage, or even an explosion.
  2. Secure Connections: Ensure the probes are securely connected to the multimeter and the battery terminals to prevent accidental short circuits.

Handle with Care

  1. Wear Protective Gear: Wear gloves and eye protection to guard against potential chemical leaks, sparks, or electrical shocks. If damaged, batteries can emit harmful substances.
  2. Inspect the Battery: Before testing, inspect the battery for any signs of physical damage, swelling, or leakage. Do not test a damaged battery, as it poses a higher risk of hazards.
  3. Use Insulated Tools: When opening the laptop and handling the battery, use tools with insulated handles to reduce the risk of electrical shock.

Work in a Safe Environment

  1. Dry Workspace: Ensure your workspace is dry to avoid any risk of electrical shock. Moisture can conduct electricity and increase the risk of accidents.
  2. Good Ventilation: Perform the test in a well-ventilated area to avoid inhaling any fumes that may be released from the battery, especially if it is damaged.
  3. Clear Area: Keep your workspace clear of flammable materials and clutter that could cause accidents or obstructions.

Proper Handling of Batteries

  1. Disconnect Properly: Always disconnect the laptop from any power source and shut it down completely before removing the battery.
  2. Avoid Extreme Temperatures: Do not test the battery in extremely hot or cold environments, as temperature extremes can affect the battery’s performance and safety.
  3. Dispose Responsibly: If the battery is defective or damaged, dispose of it properly according to local regulations. Please do not throw it in the regular trash, as it can be hazardous.

Electrical Safety

  1. Understand Your Multimeter: Know its settings and functions before using the multimeter. Incorrect settings can lead to inaccurate readings or damage to the device.
  2. Check the Multimeter: Before use, check the multimeter for any signs of damage, such as frayed wires or cracks. A damaged multimeter can give inaccurate readings and pose a safety risk.
  3. Calibration: Ensure your multimeter is properly calibrated and in good working condition. An improperly calibrated multimeter can provide false readings.

Battery Specific Precautions

  1. Battery Chemistry: Be aware of the type of battery chemistry (e.g., lithium-ion, nickel-metal hydride) you are dealing with, as different types have specific handling and testing requirements.
  2. Monitor for Heat: Stop immediately if the battery becomes excessively hot during testing. Overheating can indicate a short circuit or other issues.
  3. Avoid Physical Stress: Do not bend, puncture, or apply excessive force to the battery, as this can cause internal damage and create safety hazards.


Testing your laptop battery with a multimeter is straightforward and can help you diagnose potential issues and maintain your device’s performance. Following this guide, you can accurately assess your battery’s health and take necessary actions to prolong its life.

Regular testing and proper battery care will ensure your laptop remains reliable and efficient for years.

Frequently Asked Questions

How often should I test my laptop battery with a multimeter?

You should test your laptop battery with a multimeter every 3 to 6 months. Regular testing allows you to monitor the battery’s health and performance, identify potential issues early, and take appropriate action to maintain or replace the battery as needed. Additionally, if you notice any sudden drops in battery performance, unusual heating, or the battery not holding a charge, it is a good idea to test it immediately.

Can I test my laptop battery without removing it from the laptop?

Yes, you can test the laptop battery without removing it from the laptop, but it depends on the design of your laptop. Many laptops allow you to access the battery terminals without removing the battery. You’ll need to identify the positive and negative terminals and place the multimeter probes directly on them while the battery is still connected. However, be extra cautious to avoid short-circuiting any components. If unsure, refer to your laptop’s manual or consult a professional.

How often should I test my laptop battery with a multimeter?

Testing your laptop battery every 3 to 6 months is a good practice. Regular testing helps you monitor the battery’s health and performance over time, allowing you to take action before any issues become severe. Additionally, if you notice a significant decrease in battery life, unexpected shutdowns, or your laptop isn’t holding a charge as well as it used to, you should test the battery immediately. Regular testing can help you identify and address problems early, potentially extending the overall lifespan of your battery.

Alex Klein Author


Alex Klein is an electrical engineer with more than 15 years of expertise. He is the host of the Electro University YouTube channel, which has thousands of subscribers.