Xiaomi Redmi Note 9 Pro is one of the most popular mid-range smartphones, but even its reliable battery capacity of 5020 mAh eventually loses capacity. If the phone runs out in half a day, turns off at 20-30% charge or the case is swollen, it’s time to change the battery. In this article, we will discuss how to do it yourself without contacting the service center.
Replacing the battery on the Redmi Note 9 Pro requires care, but it’s no more difficult than replacing the screen with an iPhone. The key is to pick up the right part, prepare the tools and follow the instructions. We will tell you which battery to choose (original or analog), how to safely disassemble the phone, disable the old battery and install a new one, and give tips on calibration after replacement.
⚠️ Important: if the battery is swelled or deformed, do not try to pierce or bend it - this can lead to fire.
1. Signs that the battery needs to be replaced
How do you know if the Redmi Note 9 Pro battery has run out of life and needs to be replaced?
- 🔋 Phone's running out of power. 3-4 One hour with moderate use (previously kept a day or two).
- 📉 The percentage of charge “jumps” (for example, from 40% immediately drops to 15%).
- 🔌 The device is switched off when 20-30% charge and not activated without recharging.
- 🔥 The phone body swelled (notably on the gap between the screen and the back cover).
- ⚡ Charging is very slow or the phone does not recognize the charger.
- 🌡️ The phone gets very hot during charging or playing.
If you see at least 2-3 signs from the list, the probability of battery wear is close to 100%, you can check the exact state of the battery through an engineering menu or applications like AccuBattery (showing real capacity and wear in percentage).
⚠️ Warning: If your phone stops turning on after it's completely discharged, don't rush to buy a new battery. 1-2 Sometimes the battery controller falls asleep and needs to be forced to start.
2. Which battery to choose for the Redmi Note 9 Pro
There are three types of batteries available on the market for the Redmi Note 9 Pro:
- Original (OEM) — The battery is manufactured in the same factories as the Xiaomi battery, and the marking must be the same as the native one (BM4X or BM4Y Cost: 1500-2500 for different audits ₽.
- Premium analogues are the Baseus, Remax, Patona brands, often exceeding the original in capacity (up to 5200 mAh), but require review checks. Price: 1000-1800 ₽.
- Budget equivalents are unknown Chinese brands, low quality and rapid wear risk, cost: 600-1200 ₽.
We recommend choosing the original battery or proven analogues with a capacity of at least 5000 mAh.
- 🔍 Labeling – should match the native battery (see the old battery sticker).
- 📦 Set – in the set should be adhesive strips for fixation.
- 🔋 Contacts – check that the connector matches the connector on the phone board.
| Type of battery | Capacity | Term of service | Price. | Where to buy |
|---|---|---|---|---|
| The original (Xiaomi) | 5020 mAh | 2-3 years | 1500–2500 ₽ | Official stores, AliExpress (verified sellers) |
| Baseus/Remax | 5000–5200 mAh | 1.5-2.5 years | 1000–1800 ₽ | AliExpress, Beru, Wildberries |
| Budgetary analogue | 4500-5000 mAh | 1-1.5 years | 600–1200 ₽ | AliExpress, local radio market stores |
Do not buy batteries with a capacity above 5200 mAh - this is either a hoax (the real capacity is lower), or the battery will not fit in the case of the phone.
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Before buying, check the battery reviews by photo of the connector. Fraudsters often sell batteries from other Xiaomi models (for example, from the Redmi Note 8 Pro), which look similar but do not fit the connector.
Battery replacement tools
To replace the battery with the Redmi Note 9 Pro, you will need:
T3 (Torx) screwdriver for the rear cover screws
Plastic mediator or guitar mediator to disconnect the cover
Suction (optional, to raise the screen)
Tweezers to detach plumes
Isopropyl alcohol (90%+) for cleaning contacts
Thermoclee or bilateral tape to fix the new battery
Dryer or thermo-air station (for softening the glue)
Gloves (recommended for safety)-->
Where to buy tools:
- 🛒 Smartphone repair kits – sold on AliExpress, Chip and Deep or Citilink (cost 300-800) ₽).
- 🔧 Individual tools are screwdrivers. T3 Mediators can be found in the store.
- 🔥 Hair dryer - suitable construction or even household (but with a capacity of at least 1500 W).
If you do not have experience disassembling phones, it is better to buy a special kit for Xiaomi - it already has everything you need, including a suction cup and plastic shoulder blades.
⚠️ Warning: Do not use metal tools (knives, screwdrivers) to lid the lid, they will scratch the body and can damage the plumes!
Step-by-step instructions for replacing the battery
Now, to the process itself, follow the instructions carefully so that you don't damage your phone.
Step 1: Turn off the phone and prepare
1. Turn off the Redmi Note 9 Pro completely (press the power button and select “Switch off”).
2. Extract. SIM-card and memory card (if installed).
3. Warm the back cover with a hair dryer for 2-3 minutes (temperature ~60 ° C) - this will soften the glue.
Step 2: Removal of the back cover
1. Insert a plastic mediator into the gap between the lid and the housing (start at the bottom edge where the charging connector is).
2. Carefully drive the mediator around the perimeter, separating the lid. If it does not respond, warm up again with a hair dryer.
3. After removing the lid, put it aside - it will be useful for reverse assembly.
What to do if the lid is not removed?
Step 3: Disconnect the old battery
1 Unscrew 10 screws (screwdriver T3), fixing the metal plate above the battery.
2. Gently gently slap the plate and put it aside.
3. disconnect the battery connector with a plastic blade (do not pull the wires!).
4. Put the battery on and remove it. If it's glued, heat it with a hair dryer and use a mediator.
Step 4: Installation of a new battery
1. Remove the protective film from the new battery and glue it to a double-sided tape (comes with the kit).
2. Connect the battery connector to the motherboard.
3. Set the metal plate back and twist the screws.
Step 5: Assembly of the phone
1. Warm up the edges of the body with a hairdryer and press the back cover so that the glue grabs.
2. twist two screws at the charging connector (they can fall out during disassembly).
3. Turn on the phone and check if the new battery is recognized.
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Don't turn on the phone right after assembly! Let the glue cool for 10-15 minutes or the lid may come off.
Calibration of the battery after replacement
The new battery needs to be trained so that the charge controller correctly displays the percentage of charge.
- Completely discharge the phone before automatically shutting down.
- Charge it to 100% without interruptions (use the original RAM).
- Turn off the charger and let the phone work for 1-2 hours.
- Repeat the discharge-charging cycle 2 more times.
Once calibrated, the phone will be more accurate in showing the charge level. If the percentages still jump, reset the battery controller settings through the engineering menu:
##4636## → Battery information → Reset calibrationTip: the first 3-5 cycles of charging avoid intense loads (games, video) – this will prolong the life of a new battery.
6. Frequent mistakes and how to avoid them
Even with a careful replacement, you can make mistakes that will cause your phone to malfunction.
- ⚡ Screen plume damage -- occurs when you push the mediator too hard when you take the lid off. Solution: Use a thin plastic tool and take your time.
- 🔌 The battery contacts break if you pull the wires instead of the connector. Solution: disconnect the battery with a plastic blade only.
- 🔥 Overheating of the battery - if you heat it with a hairdryer for too long. Solution: keep the hairdryer at 10 cm and don't heat one dot longer than 20 seconds.
- 📱 The lid is loosely attached if the glue is not grasped well. Solution: warm the edges after assembly and press the lid with a weight (for example, a book) for 30 minutes.
If the phone is not switched on after replacement:
- Check if the battery connector is connected.
- Make sure all plumes are in place (especially the power plume).
- Connect your phone to charge for 10-15 minutes – sometimes a new battery needs to be “waked up.”
⚠️ Warning: If the phone turns on after the replacement but discharges quickly, check if the new battery is swelling (this happens with defective batteries!
7.How much does it cost to replace the battery in the service
If you're not sure about your abilities, you can contact the service center.The cost of replacing the battery with the Redmi Note 9 Pro in 2026:
| Type of service | Cost of work | Battery cost | Totally. | Guarantee |
|---|---|---|---|---|
| Official Xiaomi service | 1500–2500 ₽ | 1500–2500 ₽ (original) | 3000–5000 ₽ | 6–12 months |
| Informal service | 800–1500 ₽ | 1000–1800 ₽ (analogue) | 1800–3300 ₽ | 1-3 months |
| Self-sustaining replacement | 0 ₽ | 600–2500 ₽ | 600–2500 ₽ | Depends on the store. |
Self-replacement costs 2-3 times cheaper, but deprives you of warranty. If the phone is warranty, it is better to contact the official service - otherwise the warranty will burn.
Where to look for services:
- 📍 Official - on the Xiaomi website in the section "Service centers».
- 🔧 Unofficial – check reviews on Yandex.Maps or 2GIS.
- 🛒 Parts stores – some offer on-site replacement (e.g. Fix Price, Connected Service»).