Most laptop batteries slide out or unscrew from underneath
Replacing a laptop battery is one of the easiest repairs you can do yourself. The battery sits in a compartment on the bottom or side of your machine, held in place either by a latch you slide or screws you unwind. You do not need special tools or technical knowledge—just the right replacement battery and five minutes of your time.
The hardest part is usually finding the correct battery model for your specific laptop. Manufacturers use different part numbers for nearly identical batteries, and ordering the wrong one means sending it back. Before you buy anything, you need to know your laptop's exact model number and the battery part number it originally came with.
Key Takeaways
- Find your laptop model number in Settings (Windows) or System Information (Mac), then search the manufacturer's website for the correct battery part number.
- Power off your laptop completely, unplug it, and wait a few minutes before opening the battery compartment to let any residual charge drain.
- Most batteries either slide out with a latch or are held by one or two screws on the bottom panel—check your manual or manufacturer's support page to see which type yours is.
- Insert the new battery in the same orientation as the old one, making sure the connectors align, then slide or screw it back into place.
- Plug in your laptop and let it charge for at least two hours before using it on battery power to calibrate the new battery.
Find your laptop model and the correct battery part number
Open your laptop's system information to locate the exact model number. On Windows, press the Windows key and type "System Information," then look for "System Model" in the window that opens. On a Mac, click the Apple menu, select "About This Mac," and note the "Model Identifier" listed there.
Go to your laptop manufacturer's support website—Dell, HP, Lenovo, Apple, Asus, or whoever made yours—and search for your model number. Look for a "Specifications" or "Parts" page that lists the original battery part number. Write this number down exactly as it appears. Do not assume two batteries with similar names are the same; manufacturers often use different part numbers for batteries that look identical but have different voltage or capacity ratings.
Order the replacement battery from the manufacturer's official store, or from a reputable retailer that clearly states it is compatible with your exact model. Avoid unmarked or generic batteries, which may not fit properly or could damage your laptop's charging circuit.
Power down completely and let the laptop cool
Shut down your laptop fully—do not just close the lid or put it to sleep. Click the power menu and select "Shut Down" (Windows) or "Shut Down" (Mac), then wait for the screen to go black and stay black for at least ten seconds.
Unplug the power adapter from the laptop. If your machine has a removable power cord, disconnect that too. Wait two to three minutes before opening the battery compartment. This allows any residual electrical charge in the system to dissipate, which makes the swap safer and prevents accidental damage to the charging circuit.
Locate and open the battery compartment
Flip your laptop upside down and look at the bottom panel. You will see either a small latch or a row of screws. Check your laptop's manual or the manufacturer's support page to confirm which type yours has—this takes 30 seconds and prevents you from looking for a latch that does not exist.
If your battery is held by a latch, you will see a small plastic or metal lever on one or both sides of the battery compartment. Slide the latch (or latches) away from the battery. The battery should pop up slightly or slide out partway. Gently pull it the rest of the way out by the edges—never grab the connectors or the top of the battery itself.
If your battery is held by screws, use a Phillips head screwdriver (usually size #0 or #1) to remove them. Screws are often very small, so place them in a small cup or on a piece of tape so you do not lose them. Once the screws are out, gently lift the battery straight up and out of the compartment.
Install the new battery and find it
Before you insert the new battery, look at the connectors on the old one and the new one. They should be identical—same shape, same number of pins. If they look different, stop and double-check that you ordered the correct part number. Inserting a battery with mismatched connectors can short-circuit your laptop.
Hold the new battery so the connectors face into the laptop compartment. Align the connectors with the socket inside the compartment, then slide or lower the battery straight in. You should feel it seat fully—it will not wiggle or sit at an angle. If it does not fit smoothly, remove it and check the orientation again. Do not force it.
If your battery uses a latch, slide it back toward the battery until you hear or feel a click. If your battery uses screws, replace them in the same holes, tightening them snugly but not hard—you can strip the threads if you over-tighten small screws like these.
Charge the new battery and check the system
Flip your laptop right-side up, plug in the power adapter, and turn the machine on. You should see a charging indicator light (usually on the power button or near the battery compartment). Let the laptop charge for at least two hours before you unplug it and use it on battery power.
During the first charge, your laptop's operating system learns the capacity of the new battery. If you unplug it too soon, the system may not calibrate correctly and will show inaccurate battery percentage readings. After the first full charge, the battery should report its health and remaining time accurately in your system settings.
If the laptop does not recognize the new battery after two hours of charging, or if the charging light does not turn on, unplug the power adapter, wait one minute, and plug it back in. If the problem persists, the battery connectors may not be fully seated. Power off, remove the battery, and reinstall it, making sure the connectors click into place.
When to call a professional instead
If your laptop has a non-removable battery (common in newer MacBooks, some Ultrabooks, and gaming laptops), the battery is glued or soldered to the motherboard. Opening the case yourself can damage the display, keyboard, or internal components. Contact the manufacturer or a certified repair shop instead.
If you remove the battery and see corrosion, burn marks, or liquid damage inside the compartment, do not install a new battery. The charging circuit itself may be damaged, and a new battery could fail or overheat. Take the laptop to a repair technician for diagnosis.
If the new battery does not charge after you have reinstalled it twice and waited through a full power cycle, the charging port or motherboard may be faulty. This is beyond a battery replacement and requires professional service.
Frequently Asked Questions
How long does a laptop battery usually last before it needs replacing?
Most laptop batteries last two to four years of regular use before they hold noticeably less charge. You will notice the laptop shuts down sooner than it used to, even after a full charge. Check your battery health in Settings (Windows: search "Battery Report") or System Information (Mac: hold Option and click the battery icon) to see the current capacity compared to the original.
Can I use a third-party or off-brand battery instead of the manufacturer's?
Third-party batteries are cheaper but carry more risk. They may not fit as snugly, could have different voltage ratings that confuse your charging circuit, or may fail sooner. If you choose a third-party battery, buy from a seller with clear return policies and good reviews specific to your laptop model, not a generic seller.
What should I do with the old battery?
Laptop batteries contain lithium and should not go in the trash. Take the old battery to an electronics recycling center, a Best Buy (which accepts them for free), or contact your local waste management authority for a drop-off location. Some manufacturers also accept old batteries by mail if you register on their website.
Will replacing the battery void my warranty?
If your laptop is still under manufacturer warranty, opening the case yourself may void it. Check your warranty terms on the manufacturer's website or contact their support line before you open the bottom panel. If the battery is still covered, the manufacturer will replace it for free or a small fee.
Why is my new battery not charging?
The most common cause is connectors that are not fully seated. Power off, remove the battery, and reinstall it, pushing firmly until you hear a click. If that does not work, check that you ordered the correct part number for your model. If the connectors look bent or damaged, contact the seller about a replacement.