How to Replace a Laptop Battery: Complete Compatibility, Safety & Buying Guide

When your laptop dies quickly, shuts down while still showing charge, or only runs plugged in, the battery has reached the end of its life. Replacement beats repair: confirm the battery is the problem, match a new pack by part number, voltage, and connector, then swap it in. This guide covers each step, plus safety rules and what to buy.

Replacing a laptop battery is one of the few repairs most people can do at home, and it follows a fixed path. First, check the battery's health to confirm it's the problem, not a settings issue. Second, find the exact part number and match the voltage, connector, and capacity. Third, decide between an OEM pack and a quality aftermarket pack. Then install it safely, run a full charge cycle to calibrate the gauge, and recycle the old pack properly. The whole job takes 15 to 45 minutes on most laptops, and the battery itself is the only real cost.

How to Know When Your Laptop Battery Needs Replacing

Batteries are consumable parts. A standard lithium-ion laptop pack is rated for roughly 300–500 full charge cycles, and after that it holds noticeably less charge than when it was new. Long-life packs, such as HP's long-life batteries, are built for up to 1,000 cycles, but most consumer laptops ship with a standard pack.

A charge cycle is one full discharge and recharge. Run the laptop down to 50% twice and that counts as one cycle, not two. Most people reach the 300-cycle mark in two to three years of daily use, which is why a battery that once lasted six hours now manages two.

The signs of a worn-out battery are easy to spot once you know what to look for:

On Windows, you can confirm with a built-in tool. Open a command prompt and run powercfg /batteryreport. Windows saves an HTML report to your user folder. Open it and compare two numbers: Design Capacity, which is what the pack held when new, and Full Charge Capacity, which is what it holds today.

The rule of thumb: when full charge capacity sits below about 80% of design capacity, the battery has reached the end of its useful life. On a Mac, hold the Option key, click the Apple menu, then open System Information and Power. Cycle Count and Condition are listed there, and "Service Recommended" means replace. MacBook packs are rated for a set cycle count that varies by model, and recent MacBook Pro models are rated for 1,000.

I check the battery report before buying anything. It takes two minutes and tells you whether you're fixing a battery problem or a settings problem, and that changes what you do next.

If the report looks healthy but the laptop still dies fast, the drain comes from software and settings, not the pack. Our guide on why your laptop battery drains fast walks through the fixes.

How to Find a Compatible Replacement Battery

The most important step in a battery replacement is matching the pack to your exact machine. Match the part number, not just the laptop model name. The same model line often shipped with several different packs depending on year and configuration, so "Pavilion 15" alone covers a dozen batteries.

You can find the part number in four places:

1. The battery label. On removable batteries, slide the pack out and read the label. On internal batteries, you'll see it once the bottom panel is off.
2. The service manual for your model. Manufacturers publish these on their support sites, and they list the original battery part.
3. The manufacturer's support site. Enter your machine's unique identifier and it shows the battery that shipped with your configuration.
4. The laptop's underside label. It lists the model name plus the unique identifier you need for the lookup above.

Once you have the number, match three things: the part number, the voltage (V), and the connector. If those three match, the battery fits. Capacity (mAh or Wh) can be equal or higher, and higher just means longer runtime.

The mistakes that cause returns are always the same three. Ordering by model name alone, which spans several packs. Swapping in a pack with a different voltage. And assuming the connector matches when it doesn't. Matching the part number avoids all three.

I match the part number even when the model name looks right. A number removes the guesswork a name can't.

What if the original part was discontinued? Most packs carry several equivalent numbers. An HP HT03XL, for example, is also listed as L11119-855, L11421-542, and HSTNN-UB7J. Search by the pack's own code and you'll usually find a current equivalent.

Can't find the number at all? Search by the laptop model instead, then confirm by sight. The listing photos should show the same shape, the same connector, and the same label layout as your old pack. On our collection pages, type the part number into the search box and the results show every pack that carries it, including equivalents from other lines.

Some laptops also carry a sticker in the battery bay itself, right next to where the pack sits. Take a photo of whatever label you find before you order. It gives you something to check the new pack against when it arrives.

Need the full walkthrough? Our guide on how to find the right replacement battery for your laptop goes through every method step by step.

Reading Battery Specs: Voltage, Capacity, Connector

Battery labels pack a lot into a few lines. Here's what each spec means and the rule for matching it:

mAh and Wh are two ways to measure capacity. mAh (milliamp-hours) ignores voltage. Wh (watt-hours) includes it, so Wh is the fairer comparison between packs of different voltages. A 7.6V pack rated 4,070mAh stores about 31Wh, and a 41Wh pack of the same part-number family simply runs longer. When two packs share a part number but differ in Wh, pick the higher Wh. It's the same fit with more runtime.

Here's the same check on a real pack. The Dell GJKNX battery lists several numbers, GJKNX and GD1JP among them, and fits Latitude 5480 through 5590. Match GJKNX and the voltage, connector, and bay size all follow. The part number bundles the three checks into one.

One rule never changes: keep the voltage identical to the original. A different voltage can stop the laptop charging or damage the charging circuit. If you want more runtime, raise the capacity, not the voltage.

OEM vs Aftermarket Replacement Batteries

Two labels cover almost everything on the market. OEM (original equipment manufacturer) batteries are branded and sold by your laptop's maker. It's the exact pack your machine shipped with, and it's priced accordingly.

Aftermarket batteries are made by third parties to match your laptop. A quality aftermarket pack uses the same lithium-ion cells, the same voltage, connector, and form factor, and the same kind of protection circuitry as the original, at a lower price. Quality varies between suppliers, so where you buy matters as much as what you buy.

What separates a good pack from a bad one is inside: the cells and the protection circuit. That small board stops overcharging, over-discharging, short circuits, and cell imbalance. The logo on the case doesn't protect the cells. The circuit does.

Whatever you buy, check three things on the listing: the part number family, the warranty, and the return window. If a listing doesn't name the part number family, or its warranty covers less than a year, keep looking.

OEM makes sense while the laptop is new or still under the maker's warranty. Once the laptop is out of warranty and the maker's price stops being justified, a quality aftermarket pack is the sensible pick.

For an out-of-warranty laptop, I'd buy a quality aftermarket pack every time. With OEM you're mostly paying for the logo.

Every battery in our laptop battery collection is tested for fit and safety and covered by a 1-year limited warranty against manufacturing defects. Returns are accepted within 30 days of delivery. The full comparison, including what to check on any listing, is in our OEM vs aftermarket guide.

How to Replace a Laptop Battery Safely

Replacement breaks into two paths depending on your laptop's design. A release latch on the underside means a removable pack. No latch, and the battery is inside.

Internal batteries, the design on most laptops today, need you to open the bottom panel. You'll need a small Phillips screwdriver (#0 or #00), a plastic pry tool, and a tray or cup for screws. Touching a metal object before you start discharges static. A wrist strap is nice to have but not required.

1. Power off and unplug. Remove docks, USB devices, and SD cards.
2. Remove the bottom-panel screws. Some hide under rubber feet, so peel those gently. Note which screw came from which hole. Lengths differ.
3. Lift the panel. Work the plastic pry tool into a corner and lift. Don't use metal. It scratches the case and can short a contact.
4. Disconnect the battery cable from the board first, before touching anything else.
5. Unscrew the pack and lift it out flat. Never bend or puncture it, even if it looks puffy.
6. Set the new pack in place, screw it down, and reconnect the cable.
7. Snap the panel back on and replace the screws.
8. Plug in and charge to 100% before the first use.

After the install, the gauge needs to learn the new pack. Charge it fully, run it down to about 10%, then charge it again. One or two cycles is enough for the laptop to report runtime correctly. After that, the usual habits apply: keep the charge between about 20% and 80% on most days, and avoid sitting at 100% on the charger around the clock. Both habits slow capacity loss.

If a brand-new pack looks weak on day one, I calibrate before I blame the battery. Most of the time the battery is fine and the gauge is wrong.

If the new pack isn't recognized at all, check that the cable is seated. Then try an EC reset: power off, unplug, hold the power button for about 30 seconds, and boot again. If the maker offers a BIOS update for your model, apply it.

Model-specific steps vary. Our Dell, HP, and Lenovo guides cover each family's quirks.

Swollen Battery: Stop, Remove, Dispose

The signs are visible from the outside: a trackpad that no longer clicks or sits raised, a bottom panel that bulges or won't close flush, a laptop that rocks on a flat surface. Open it up and the pack itself looks puffy instead of flat.

Swelling happens when gas builds up inside the cells, a process called outgassing. Age, heat, overcharging, physical damage, or a manufacturing defect can trigger it. The gas means the cell chemistry has broken down, and the pack can no longer be trusted.

What to do: unplug the laptop. If the battery is removable and comes out without force, remove it and set it on a cool, dry, non-flammable surface, ideally a metal container. If it's internal or stuck, have someone experienced remove it. Never press on a swollen pack or try to flatten it. If anything leaks from the pack, don't touch it with bare skin.

Disposal needs special care. Damaged lithium-ion batteries don't go in household trash. The U.S. EPA recommends taping the terminals and taking the pack to a household hazardous waste program or a certified electronics recycler.

Full details, including how to pick a safe replacement, are in our swollen laptop battery guide.

Choosing the Right Battery for Your Brand

Part numbers, bay designs, and removal steps differ by manufacturer. Start with your brand for the exact codes, then check the matching collection to order.

Dell

Dell laptops carry a model name and a service tag on the underside label. Enter the service tag on Dell's support site and it shows the battery your machine shipped with. Dell part numbers are short codes printed on the pack, like GJKNX or 722KK. Latitude is the business line with several part numbers per generation. Inspiron is the highest-volume consumer line. XPS uses slim internal packs, and Alienware and G-series gaming models take high-capacity batteries. Examples from our shelves: GJKNX for Latitude 5480/5580, H5CKD for Latitude 3510 and Inspiron 5505, and 722KK for XPS 13 9310. See our Dell battery replacement guide, then browse the Dell collection and the Alienware collection.

HP

HP prints a model name and a product number on the underside label. Enter that P/N on HP's support site and you'll see the battery spec your machine shipped with. HP batteries carry codes like HT03XL plus part numbers like L11119-855, and several lines shipped with more than one pack. Pavilion is the highest-volume consumer line. Envy and Spectre use slim internal packs. EliteBook and ProBook are the business lines with long-life options, and Omen and Victus take high-capacity gaming packs. Examples include HT03XL for Pavilion 14/15/17, CX03XL for EliteBook x360 830 G7/G8, and SU06XL for Spectre x360 15. See our HP battery replacement guide, then browse the HP collection.

Lenovo

Lenovo laptops carry a model name and a machine type model (MTM) number. ThinkPad packs also carry a FRU number, and many ThinkPads shipped with several capacity options, so the part or FRU number decides which pack fits. ThinkPad is the largest range. IdeaPad is the high-volume consumer line. Legion covers gaming, and Yoga convertibles use slim, model-specific packs. Examples include 45N1006/45N1007 for ThinkPad T420/T430, L18C4P71 for X1 Carbon 7th/8th Gen, and L16M4P60 for Yoga 920. See our Lenovo battery replacement guide, then browse the Lenovo collection.

A few examples from our catalog:

Prices as of August 2026. Confirm the part number against your old pack's label before ordering. If your exact pack isn't listed, search the collection by part number — each brand collection carries the full range.

What a Replacement Costs: DIY vs a Repair Shop

The battery is the main cost. Packs in our laptop battery collection currently run from $39.99 to $99.99. Do the install yourself and that's the whole bill.

OEM packs from laptop makers typically cost more, usually $60–$150 depending on model. Paying a repair shop typically adds $30–$75 in labor.

Worth replacing? If the battery sits below about 70–75% of its original capacity and the laptop otherwise does what you need, yes. A $40–$70 pack buys two to four more years of use, far less than a new laptop. If the laptop already struggles with your daily work, put the money toward a new machine instead.

Run this check before you spend: battery below about 75% of original capacity, laptop under six or seven years old, and the pack price under about a quarter of a new laptop's cost. Three yeses and replacing is the smart move. Browse the laptop battery collection and check your part number against the label before ordering.

Whatever route you pick, recycle the old pack. Many electronics stores and city programs take lithium-ion batteries for free, and the swollen battery section above covers the safety rules.

Frequently Asked Questions

References & Sources

• Dell — How to Generate a Battery Report Using the POWERCFG Command. Supports the Windows battery report steps and the design-capacity vs full-charge-capacity comparison.
• Apple — Determine battery cycle count for Mac laptops. Supports the Mac battery health check and the cycle-count benchmark used in this guide.
• HP — HP Consumer Notebooks: Understanding Battery Warranty. Supports the 300-cycle rating for standard packs and the 1,000-cycle rating for long-life packs.
• U.S. EPA — Used Lithium-Ion Batteries. Supports the safe handling and disposal guidance for old and damaged batteries.

More from the Laptop & Notebook Battery guide hub:

• → Dell Laptop Battery Replacement
• → HP Laptop Battery Replacement Guide
• → Lenovo Laptop Battery Replacement: ThinkPad, IdeaPad & Legion
• → Swollen Laptop Battery: Is It Dangerous and What to Do
• → How to Find the Right Replacement Battery for Your Laptop
• → OEM vs Aftermarket Laptop Batteries
• → Why Your Laptop Battery Drains Fast (and How to Fix It)