Where is the battery located on the laptop motherboard and how to replace it yourself

Why can a laptop go crazy without a small battery?

Have you ever encountered a situation where, after turning off the laptop, the date and time are lost, and when you turn it on, the system asks you to go into the BIOS and configure the settings again? The culprit of these problems is tiny CMOS battery on the motherboard. It powers a memory chip that stores BIOS/UEFI settings even when the device is unplugged.

This battery is like an alarm clock on your phone: while it is working, everything goes according to plan, but as soon as it runs out, chaos begins. In laptops its resource is limited: on average CR2032 (the most common type) serves from 3 to 10 years depending on the model and operating conditions. However, few know where exactly to look for it, especially in compact cases of ultrabooks or gaming laptops.

In this article we will figure out how to find the battery on a laptop motherboard - from budget Lenovo IdeaPad up to bonus Dell XPS or MacBook Pro (yes, they also have an analogue!). We’ll also find out whether it’s possible to do without disassembling the case and what to do if the battery is soldered.

Types of batteries in laptops: what they are and what they look like

Not all CMOS batteries are created equal. They can be divided into three main categories, each of which requires a different approach to replacement:

• 🔋 Removable tablets - standard lithium cells CR2032, CR2026 or CR2016. Found in 80% of laptops (for example, HP Pavilion, Acer Aspire). They are easy to remove with your hands or tweezers.
• 🔌 Soldered batteries - miniature lithium-polymer batteries in a sealed case (often in MacBook, MSI or Gigabyte game models). Requires soldering or switching to an external adapter.
• 🔋🔌 Hybrid solutions — removable connector with a connected battery (found in some Lenovo ThinkPad or Dell Latitude). You can disconnect it without soldering, but you need to be careful.

As a rule, removable batteries are marked - look for inscriptions like 3V, CR2032 or manufacturer's logo (for example, Maxell, Panasonic). Soldered ones are often hidden under thermal pads or metal shields, and their contacts can be disguised as other board elements.

Where to look for the battery: 5 typical places on the motherboard

The location of the CMOS battery depends on the design of the laptop. In most cases it is located in one of these places:

1. Under the keyboard - classic arrangement for most models (for example, Lenovo ThinkPad T480 or HP EliteBook). The battery is visible immediately after removing the keyboard, often next to the touchpad connector.
2. Under the bottom cover - in laptops with a non-removable keyboard (for example, Asus ZenBook or Dell XPS 13). Look for it near the power connector or under the metal screen.
3. Near RAM - in models with access to RAM through a hatch (for example, Acer Nitro 5). The battery can be glued to the board or secured with a plastic holder.
4. Under the cooling system - in compact ultrabooks (for example, Microsoft Surface or Huawei MateBook). Here it is often confused with capacitors due to its similar size.
5. In a separate module - in some business laptops (for example, Lenovo ThinkPad P-series) the battery is placed on a separate board with a connector.

If you're not sure where exactly to look, take a look at markings on the board. Often next to the battery there are inscriptions like CMOS, RTC (Real-Time Clock) or BIOS_BAT. In laptops Apple (until 2015) it can be hidden under the battery - it will have to be disconnected.

How to distinguish a CMOS battery from other elements?

It is always round (diameter 20 mm) or rectangular (the size of a little finger), marked 3V. Capacitors and resistors are usually cylindrical or cubic, without voltage labels.

Laptop brand	Typical battery location	Battery type	Replacement difficulty (1-5)
Lenovo ThinkPad	Under the keyboard, next to the touchpad	CR2032 (removable)	2
Dell XPS 13/15	Under the bottom cover, under the metal screen	CR2032 or soldered	4
HP Pavilion/Omen	Near the RAM or M.2 slots	CR2026 (removable)	3
Asus ROG Zephyrus	Under the cooling system	Soldered or with connector	5
Apple MacBook (2015-2020)	Under the battery or on a separate board	Soldered lithium polymer	5

Signs of a low battery: when is it time to change it

A CMOS battery does not “die” suddenly - it makes itself known in advance. Here are the key symptoms that indicate the need for replacement:

• ⏰ Time and date get lost every time you turn off the laptop (even if it was in sleep mode).
• 🔧 BIOS is reset to factory settings - for example, the boot order disappears or Secure Boot is disabled.
• 🖥️ Laptop won't turn on the first time — it takes several attempts or resetting the BIOS (removing the battery for 30 seconds helps).
• 🔌 Loading errors: messages like CMOS checksum error, CMOS battery failure or Date/Time not set.
• 🔋 Laptop does not keep power saving settings - for example, he forgets the screen brightness or the fan control circuit.

If you observe at least two of these signs, there is a 90% chance of a battery problem. However, before replacing, check whether the BIOS itself is at fault: update it to the latest version through the manufacturer’s official website. Sometimes crashes are caused by software errors rather than hardware ones.

⚠️ Attention: In laptops with TPM chip (For example, Lenovo with Fingerprint or Dell with BitLocker) resetting CMOS may block access to data! If you are using disk encryption, make sure you have a recovery key.

Step-by-step instructions: how to remove and replace the battery

The replacement process depends on the type of battery, but the general scheme looks like this:

Unplug the laptop and remove the main battery (if it is removable)|

Prepare an antistatic wrist strap or touch the metal body to release static|

Use a plastic spatula (or pick) to disassemble the body|

Prepare a new battery (check type: CR2032, CR2026, etc.)|Take photos of the location of the cables and screws before disassembling-->

Next, follow the algorithm:

1. Remove the bottom cover (or the keyboard, if the battery is there). The screws may be hidden under the legs - carefully pry them out. In some models (for example, MacBook) you will need a special screwdriver P5 Pentalobe.
2. Find the battery. If it is under a metal screen, unscrew it. Look for a soldered battery along the wires leading to the microcircuit RTC.
3. Remove the old battery:
   • For a removable one: carefully pry it off from the side with a screwdriver (the holder is usually spring-loaded).
   • For soldered: disconnect the connector or cut the wires (if you plan to solder).

Install a new one. For a removable one, simply insert it with the contacts facing down. For soldering, use a soldering iron with a thin tip (power no more than 30 W) or connect an external 3V adapter.

Assemble your laptop and turn it on. If the time is wrong, go to the BIOS (F2, Del or Esc at boot) and configure the settings again.

If the laptop does not turn on after replacement, check:

• Is the battery installed correctly (plus/minus are not reversed).
• Are foreign objects (for example, a forgotten screw) closing the contacts?
• Is the board damaged during disassembly (inspect for scratches or peeled tracks).

What to do if the battery is soldered: 3 alternative solutions

In modern laptops (especially Apple, MSI or Razer) The CMOS battery is often soldered to the board. If you're not ready to solder, consider these options:

• 🔌 External adapter — connect a 3V power source instead of a battery (for example, from an old PC motherboard). Minus: the wires will stick out from the case.
• 🔋 USB RTC programmer - devices like CH341A can emulate CMOS operation, but require software skills.
• 🖥️ Bypass via BIOS - some laptops (for example, Dell Latitude) allow you to disable CMOS checking in the settings. Minus: the time will be lost every time you turn it off.

If you decide to solder, use low temperature solder (For example, Sn63Pb37) and acid-free flux. Gently heat the contacts with a soldering gun (temperature no higher than 300°C) to avoid damaging the board. B MacBook The battery is often glued to the board - you will need to remove it isopropyl alcohol and a plastic scraper.

⚠️ Attention: In laptops with embedded controller (For example, Lenovo Yoga or HP Spectre) improper soldering can damage the keyboard and touchpad controls! If you are not sure, contact the service.

Common replacement mistakes and how to avoid them

Even experienced users sometimes make mistakes that lead to new problems. Here are the most common:

Error	Consequences	How to avoid
Using metal tools to remove the battery	Short circuit, failure of the south bridge	Use a plastic spatula or wooden toothpick
Installing the battery upside down	The laptop does not turn on, the battery may be swollen	Check polarity: “+” should be on top
Forgot to disconnect the main battery	Damage to the board due to static electricity	Always remove the battery and power cable before use
Soldering without protecting adjacent elements	Detachment of contact pads, damage to microcircuits	Cover adjacent components with foil or heat shrink tubing

Another typical problem is cable damage when disassembling. For example, in Asus ZenBook The touchpad cable runs directly above the battery. If you touch it, the screen may stop responding to touches. Always disconnect cables carefully by pulling the plastic connector, not the wires!

If after replacement the laptop begins to perform worse (for example, artifacts appear on the screen or the USB does not work), most likely you have damaged the graphics chip or I/O controller. In this case, only diagnostics at a service center will help.

FAQ: answers to frequently asked questions

Is it possible to do without replacing the battery if it runs out?

Technically yes, but with caveats. You can:

• Setting up the BIOS every time after turning it on (inconvenient).
• Disable CMOS checking in BIOS settings (if there is such an option).
• Use a script to automatically synchronize time over the Internet (in Windows: w32tm /resync).

However, without a battery, the laptop will lose settings every time it is disconnected from the network, and in some models (for example, Lenovo with Fingerprint) this will cause authentication to fail.

What is the lifespan of a CMOS battery in a laptop?

Depends on the type and operating conditions:

• CR2032 serves on average 5-7 years at normal temperature (20-25°C).
• In gaming laptops (eg. MSI GT76) due to heating, the period is reduced to 3-4 years.
• Soldered lithium polymer batteries last longer - up to 10 years, but they are more difficult to replace.

If the laptop is constantly connected to the network, the battery discharges more slowly (since part of the energy is taken from the power supply).

What happens if you remove the battery for a long time?

If you remove the CMOS battery more than 24 hours, will happen:

• Complete BIOS/UEFI reset to factory settings.
• Removing all user profiles in the BIOS (for example, boot passwords).
• Some laptops (eg. Dell Precision) may reset ME region, which will require flashing.

If you need to store the motherboard without a battery, it is better to short-circuit the contacts with a 10 kOhm resistor - this will prevent the capacitors from discharging.

Can I use a battery from a watch or remote control?

Theoretically yes, if she fits the type (CR2032, CR2026) and voltage (3V). However:

• Batteries from cheap remote controls are often of low quality and can leak.
• Some laptops (eg. HP EliteBook) requires a battery with low self-discharge (For example, Panasonic BR2032).
• If the battery is old (even unused), its capacity may have decreased.

It is better to buy a new battery in a trusted store (it costs 50-150 rubles).

How to check if a new battery is working?

After installation:

1. Turn on your laptop and check if the time resets after rebooting.
2. Go to the BIOS and look at the battery voltage (if there is such an item, for example, in ASUS UEFI). Norm: 2.8–3.3V.
3. Unplug the laptop for 10-15 minutes, then turn it on. If the settings are saved, the battery is working.

If the voltage is below 2.5V, the battery is defective or the contacts do not fit well.