Why the Redmi 3S Battery Fails and When to Change It
Xiaomi Redmi 3S, released in 2016, is still popular with users due to its reliable build and low price. However, even the best device faces battery degradation over time. On average, lithium-ion batteries lose up to 20% of their capacity after 300-500 charging cycles, and after 2-3 years of active use this figure can reach 40-50%.
How to know if the Redmi battery is 3S The main signs: fast discharge (smartphone sits down in a few hours even in standby mode), sudden shutdowns at 20-30% charge, bloating (noticeable by the curvature of the back cover or the difficult closure of the slot for the device). SIM-cards), overheating during charging or work.
If any of these symptoms are present, it is time to consider replacing them.
It is important to consider that Redmi 3S is equipped with a non-removable battery type BL-206 with a capacity of 4100 mAh. Xiaomi officially does not supply original batteries for this model, so the market has analogues from third-party manufacturers. The main thing is to choose a quality option so as not to face compatibility or safety problems.
Which battery to choose for Redmi 3S: original vs analogues
The original Redmi 3S batteries are long gone, but there are some good ones on the market, and the rule is not to buy the cheapest ones, because they often have low real capacity and can swell in a few months.
- 🔋 Baseus, a reliable Chinese manufacturer with good reviews, offers batteries with overheating protection.
- 🔋 Remax is a budget but quality option, often comes with replacement tools.
- 🔋 Patona – German brand, guarantees compliance with the declared capacity (4100 mAh).
- 🔋 ZMI (Xiaomi subsidiary is one of the best analogues, but it costs more than the rest.
When choosing, pay attention to the following parameters: capacity (should be at least 4000 mAh), voltage (standard for Redmi 3S - 3.85V), availability of a protection controller (prevents overcharging and short circuit).
Also make sure that the kit is double-sided tape to fix the new battery – it is often absent in cheap sets.
⚠️ Warning: Don't buy AliExpress batteries without validated reviews! Often sellers indicate overcapacity (e.g., 5,000 mAh instead of the real 3,000 mAh). CE ROHS.
| Brand | Capacity | Price (2026) | Pluses | Cons |
|---|---|---|---|---|
| Baseus | 4100 mAh | 1 200–1 500 ₽ | Reliable controller, long service life | Hard to find in offline stores |
| Remax | 4000 mAh | 800–1 000 ₽ | Low price, complete with tools | Capacity just below the original |
| Patona | 4100 mAh | 1 800–2 200 ₽ | 12 months warranty, high quality | More expensive than analogues |
| ZMI | 4100 mAh | 2 000–2 500 ₽ | Best quality among analogues | High price, rarely available |
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Before buying, check the battery with a multimeter (if possible). The voltage of the new battery should be within 3.7-3.85V. If the seller refuses to provide a test, this is a reason to doubt the quality.
Preparing for replacement: security tools and measures
Replacing the battery with the Redmi 3S requires care and the right tools. Unlike smartphones with a removable back cover, you have to disassemble the case, and that can risk damaging the plumes or the display.
- 🔧 Plastic mediator or shoulder blade - for separation of the back cover.
- 🔧 The screwdriver (PH00) — screw-off.
- 🔧 Screen suction cup - will help to lid without scratches.
- 🔧 Tweezers - to detach the plumes.
- 🔧 Isopropyl alcohol (70%+) — clean-up.
- 🔧 Hair dryer or thermo-air station - for softening the glue (optional).
Also prepare your workspace: a clean desk with good lighting, a soft fabric (so as not to scratch the screen), a screw container (they are small and easily lost). Never disassemble your smartphone on a carpet or couch - static electricity can damage the motherboard!
⚠️ Warning: If the battery is swelling, don't try to prick it or bend it! This can cause fire.
Turn off your smartphone and remove it. SIM-map|Make a backup copy of the data|Charge the battery to 30-50% (bloated battery do not charge!)|Prepare tools and the workplace|Wear an antistatic bracelet (optional)-->
Step-by-step: how to disassemble the Redmi 3S and replace the battery
The process of replacing your battery with a Redmi 3S is a series of steps, and if you've never taken a smartphone apart, you'd better practice on it or watch a video manual. Take your time, because most breakdowns are caused by haste.
Step 1 Remove the back cover
Heat the edge of the back with a hair dryer (temperature no higher than 60°C) to soften the glue. Carefully apply the lid with a plastic mediator starting at the bottom corner. Do not use force - if the lid does not respond, warm it up again. After removing, put the lid aside without touching the internal contacts.
Step 2: Spinning the screws
Under the lid, you'll see 10 PH00 screws. Unscrew them and put them in a container (preferably take a picture of the location so you don't get confused when you build them).
Step 3: Disconnect the plumes
With tweezers, carefully disconnect:
- battery plume (black connector),
- the display plume (white connector),
- camera plume (small yellow connector).
Don’t pull the wires – just for plastic fixtures!
Step 4: Remove the old battery
The battery is glued to the body. You can put a plastic blade on it and slowly pull it up. If the glue is too strong, you can put some isopropyl alcohol under the battery, it will dissolve the glue, but it won't damage the electronics. Don't use metal tools!
Step 5: Installation of a new battery
Check the contacts of the new battery for no contamination. Stick two-way tape (if any) and carefully place the battery in place. Connect the plumes in reverse order and twist the screws. Before assembly, make sure that all cables are flat and not clamped.
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The most common mistake when replacing is damage to the display plume. If the screen doesn't work after assembly, check if the white connector is tightly fixed.
Calibration of the battery after replacement: why it is important
Once the new battery is installed, it needs to be calibrated to make sure the smartphone correctly detects its charge level, and without calibration, there may be situations where the Redmi 3S suddenly turns off at 30-40% charge or shows 100%, although the actual capacity is lower.
How to calibrate:
- Charge your smartphone to 100% and leave it on charging for another 1-2 hours.
- Turn off the charger and use the phone until it is completely discharged (until it turns off itself).
- Connect the charging and charge up to 100% without interruptions.
- Repeat the discharge-charging cycle 2-3 times.
This process helps the battery controller to “learn” new capacitance parameters.
If you have problems after calibrating, try resetting through Settings → Additional → Restore and Reset → Reset. This won’t delete your data, but will restart the power management system.
What if the smartphone does not turn on after replacing the battery?
Frequent Mistakes and How to Avoid Them
Even experienced users sometimes make mistakes when replacing a battery, and here are the most common ones and ways to prevent them:
- 🔌 Display plume damage occurs when you pull too hard on the cable. Always use plastic connectors!
- 🔥 Short circuit -- happens when you touch the battery's contacts with metal tools. Use plastic blades.
- 📉 Incorrect capacity – cheap batteries often have real capacity 20 to 30 percent below the stated capacity.
- 🛠️ Loss of screws - screws at Redmi 3S Small and easily lost. Use a magnetic mat or container.
- 🔋 Incomplete shutdown of the plumes -- if you forget to disconnect the battery before work, you can burn the board!
Another common problem is that the new battery is not fixed properly, and if you don't use double-sided tape or glue, the battery can move inside the case, causing contacts to break, and in some cases, it can even cause the smartphone to reboot constantly.
⚠️ Warning: If the battery runs out in a few hours after the replacement, check if the energy-consuming app is working in the background. → Battery → Using a battery and see what consumes the charge.
Should I change the battery myself or contact the service?
Replacement of the battery with Redmi 3S Costs 2-3 times cheaper than in a service center (where the price can reach 3,000-4000). ₽ But there are times when you can trust the professionals:
- 🔧 You’ve never taken out electronics and are afraid of damaging your smartphone.
- 🔥 Battery swells or leaks (risk of fire!).
- 📱 After the replacement, there were problems with the screen, camera or charging.
- ⚡ Work warranty required (most services give 3-6 months).
If you decide to do it yourself, consider your skills realistically, for example, replacing a display plume requires much more care than replacing a battery. In the case of the Redmi 3S, the process is relatively simple, but it still requires attention to detail.
Average replacement cost in 2026:
— Independently: 800–2,500 ₽ (battery + tool).
— In service: 2,000 to 4,000 ₽ (depending on the region and components).
If the smartphone is used as a spare or for irresponsible tasks, a self-replacement may be justified.