Replacement of the battery in the thermometer Xiaomi: models, tools and step-by-step analysis

Why change the battery and when to do it?

Xiaomi thermometers are some of the most popular smart home gadgets due to their accuracy and integration with the Mi Home ecosystem. But even such devices require maintenance: over time, the battery goes down and the device stops working correctly. The first signs of discharge are unstable readings, frequent communication breaks with the application or a complete shutdown of the display (if any).

Battery life depends on model and usage. For example, in Xiaomi Mi Temperature 2 (LYWSD03MMC model), the standard CR2032 element lasts 1-2 years for daily measurements. In newer versions with Bluetooth Low Energy (BLE), power consumption is lower, but even there the battery requires replacement every 18-24 months. It is important not to wait for a full discharge: this can lead to a failure of the calibration of the sensor.

If the thermometer stopped displaying the temperature or the Mi Home app appeared notification "Low battery charge", it's time to act. In this article, we will discuss how to replace the battery in different Xiaomi models, what tools you will need and how to avoid typical errors.

What Xiaomi Thermometers Support Battery Replacement?

Not all Xiaomi thermometers allow you to replace the battery yourself. For example, in the Xiaomi Mi Temperature and Humidity Monitor 2 (model LYWSD02), the battery is soldered into a board, its replacement requires soldering and electronics repair skills.

• 🔹 Xiaomi Mi Temperature 2 (LYWSD03MMC) — battery CR2032, 5-minute replacement.
• 🔹 Smartmi Temperature and Humidity Monitor (GCLS002) — battery CR2450, need a screwdriver.
• 🔹 Xiaomi Mijia Bluetooth Thermometer (LYWSDCGQ/01ZM) — battery CR2032, latch-case.
• 🔹 Xiaomi ClearGrass Thermometer (CGDK2) — battery LR44, miniature.

To determine the model accurately, look at the back of the device — there is an article (for example, LYWSD03MMC). If there is no marking, check in the Mi Home app: go to Devices → select thermometer → Settings → Information.

⚠️ Note: In thermometers Xiaomi with index LYWSD02 (First generation battery is non-removable, and trying to replace it without soldering will cause a breakdown!

What tools and materials will you need?

Most Xiaomi models don’t need professional tools to replace the battery.

• 🔧 Plastic blade or mediator - for disassembling the body without scratches.
• 🔩 Cross screwdriver (if there are screws) - the size will suit PH00 or PH0.
• 🔋 New battery - check the type (CR2032, CR2450 or LR44).
• 🧲 Magnet or tweezers – so as not to lose small parts (screws, springs).
• 📸 Smartphone – for photographing the process (useful when assembly).

If you're replacing a battery for the first time, we recommend buying a lithium battery from a brand name (e.g. Duracell, Energizer or Panasonic) that can leak or run out quickly, and pay attention to the date of production, which means that a fresh battery will last longer.

Step-by-step: how to disassemble the thermometer and replace the battery

Consider the process using the most popular model, the Xiaomi Mi Temperature 2 (LYWSD03MMC), and the steps may vary slightly in other thermometers, but the principle remains the same.

Step 1: Disconnect from the application (optional)

Before replacing the battery, you can turn off the thermometer from the Mi Home to avoid synchronization errors.

1. Open the Mi Home app.
2. Go to the Devices. → Choose a thermometer → Settings (⚙️).
3. Press "Delete Device."

After the battery is replaced, the thermometer will automatically reconnect at the first measurement.

Step 2: Disassembly of the hull

The Xiaomi Mi Temperature 2 has two parts attached to it with latches to open it:

1. Take a plastic spatula and gently tuck the lid on the side (where there is no display).
2. Swipe around the perimeter until you hear clicks of snapping locks.
3. Remove the top of the body. Be careful - there may be a spring inside that pops out!

In models with screws (such as the Smartmi GCLS002), first unscrew them with a cross screwdriver.

Step 3: Remove the old battery

After you take it apart, you'll see the battery. CR2032, You can carefully tuck it in with a spatula or tweezers and take it out. Notice the polarity: the board usually has a marking "+" and "−".

⚠️ Warning: Don’t touch the contacts on the board with your bare hands – static electricity can damage the sensor!

Step 4: Installation of a new battery

Insert a new battery plus up (unless otherwise indicated on the board), make sure it fits tightly to the contacts, and if there is a spring in the case, make sure it doesn't move.

Step 5: Assembly of the thermometer

Carefully combine the two halves of the body and press until the click. If you have screws, twist them. Once assembled, the thermometer should automatically turn on. If that does not happen, check:

• The polarity of the battery.
• Contact density.
• The integrity of the spring (if any).

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If the thermometer does not turn on after replacing the battery, try to slightly press the case in the area of the battery compartment - sometimes the contacts are oxidized and require cleaning with alcohol.

Frequent Mistakes and How to Avoid Them

Even with the seemingly simple process, many users make mistakes that cause the thermometer to break.

Another common problem is resetting the Mi Home after the battery is changed. If the thermometer doesn't automatically connect, try:

1. Reboot the Mi Home app.
2. Remove the device and add it again (Add the device → Davies → Thermometer).
3. Check if you need a firmware update.

How to prolong the life of a battery: tips for saving energy

To change the battery less often, follow these recommendations:

• 📶 Reduce the data rate in Mi Home. By default, the thermometer sends a reading every 5-10 minutes. Change the interval by 30-60 minutes in the device settings.
• 🔌 Turn off humidity notifications if they're not needed.The humidity sensor consumes extra power.
• 🌡️ Keep the thermometer in optimal conditions: at a temperature of 0-50°C and humidity up to 80 percent. Extreme conditions accelerate discharge.
• 🔄 Update your firmware regularly. Newer versions often optimize power consumption.

Xiaomi display thermometers (like the LYWSD03MMC) use the main energy to light up, so if you don't need the screen, unplug the protective film from the sensor, which will turn off the display and prolong battery life by 20 to 30 percent.

It is also worth keeping track of the Bluetooth signal level, if the thermometer is far from the gateway (for example, Xiaomi Gateway), it will spend more energy on data transfer, the optimal distance is up to 10 meters without obstacles.

Alternative power supply: can batteries be used?

Some users are trying to modify Xiaomi thermometers by installing rechargeable batteries of the same size (such as the LiR2032) instead of CR2032 batteries.

• ⚡ Voltage: A standard battery produces 3V, and a battery produces 3.6-3.7V. This can damage the board.
• 🔋 Capacity: batteries LiR2032 have a smaller capacity (usually 60-80 mAh vs 220 mAh batteries), so they will last less.
• 🔌 Charging: to recharge you will need a soldering iron and circuits, which is not advisable for a cheap device.

If you do decide to experiment, use batteries with anti-recharge protection and control the voltage with a multimeter. However, for most users it is easier and cheaper to change a regular battery every 1-2 years.

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Using batteries instead of batteries in Xiaomi thermometers is not recommended because of the risk of damage to the board.

FAQ: Answers to Frequent Questions