The appearance of incomprehensible characters on the display of Xiaomi smart scales is always puzzling for a user who is used to the accuracy and conciseness of the Mi Fit or Mi Home interface. In particular, an error displayed as the letter “L” often confuses gadget owners, since it has no direct analogue in the usual codes of malfunctions of household appliances. In fact, this indication is an abbreviation of the English word “Low”, which in the context of electronic mechanical devices means low charge of the power elements.
Many users mistakenly believe that smart scales that consume minimal energy can run on a single battery pack for years without replacement. However, current models with Bluetooth modules and high-precision sensors require stable voltage to correctly transmit data and conduct measurements. When voltage falls below a critical threshold, the self-diagnosis system blocks the weighing and displays a warning to prevent distortion of the results or sudden shutdown in the process.
Ignoring this signal can cause the device to stop turning on altogether, and in rare cases, oxidized contacts of old batteries can damage internal electronics. In this article, we will discuss in detail why there is an L error, how to replace the batteries correctly, and what to do if the new battery does not solve the problem.
The Origin of Low Battery Code
The “L” error code on the Xiaomi Mi Body Composition Scale 2 or earlier display is a direct indication of the critically low charge of the batteries. The electronics of the device are configured to stop working until the voltage becomes insufficient to conduct accurate measurements through the strain gauges. If the scales continued to work at the limit of the battery, the error in determining the weight could reach several kilograms, which would completely devalue the functionality of the gadget.
It's worth noting that smart scales don't just consume energy when weighed. The Bluetooth module periodically scans the environment or waits for a smartphone to connect to synchronize data, which also consumes charge. LED-The display requires a significant current at the time of switching on, which is why even with rare use of the device, it is recommended to change the batteries prophylactically once a year.
⚠️ Warning: Do not attempt to “resuscitate” old batteries by heating or tapping. Using low-charge batteries can cause electrolyte leakage, which will irrevocably damage the contact weight group.
There is also a software aspect of the error: In some cases, especially after a long downtime, the balance controller may not correctly read the residual charge due to a voltage surge when turned on, in which case the device can show an "L" even on fresh batteries if they were installed incorrectly or are factory defective. It is important to understand the difference between a real discharge and a false alarm of the voltage sensor.
Algorithm of replacement of power elements
Xiaomi's weight-replacement process is technically simple, but requires a certain sequence of steps to ensure that the error is corrected.Most models run on four standard AAA batteries, although some professional versions may use the AA format. The first step is to flip the scales and open the battery compartment located on the bottom panel.
Often, users find that the compartment lid is difficult to open, and the design includes a special slot where you insert a coin or a flat screwdriver and turn it around. After removing the old elements, you need to carefully examine the contacts. If you notice white plaque or traces of oxidation, they should be carefully cleaned with a dry cloth or cotton swab, slightly moistened in alcohol.
☑️ Replacement of batteries in Xiaomi scales
When installing new batteries, it is critical to observe the polarity indicated at the bottom of the compartment. A mixed plus and minus will not only not turn the device on, but can also create a short circuit in the circuit. Once all four elements are installed, close the lid until the characteristic click. The scales should automatically turn on, conduct self-testing and show a zero value or a welcome screen.
⚠️ Warning: Never mix old and new batteries, or different types of batteries (alkaline and salt) in the same compartment, which will result in uneven current output and rapid deterioration of new cells.
Table of decoding error codes
Beyond low-charge error, the scale display can signal other conditions. Understanding these codes will help you diagnose the problem faster without having to resort to complex diagnostics. Below is a table of the main characters that may appear on the Mi Smart Scale screen.
| Code on display | Meaning | Recommended action |
|---|---|---|
| L | Low battery charge | Replace all 4 batteries with new ones |
| Err | Sensor overload or error | Make sure the user’s weight does not exceed 150 kg, stand on a hard floor |
| Lo | Weight below the minimum threshold | The weighing threshold is usually 500 grams, check the object |
| OF | Overload (Overload) | Remove the load from the scales, give the sensor a rest for 2 minutes |
Importantly, the Err error can occur not only from exceeding the maximum weight (150 kg), but also when weighing on soft surfaces, such as a carpet or long-pile linoleum. Tenzos require a rigid support to work correctly. If the scales are installed incorrectly, the sensors can produce chaotic data, which the system interprets as an error.
Calibration procedure after replacement
Once new batteries are installed, Xiaomi smart scales often require calibration procedures, which are necessary to reset the residual values in the controller’s memory and set a “zero” reference point. Without this step, the device can continue to show an error or give incorrect data about weight and fat percentage.
To perform calibration, perform the following actions:
- 🔹 Set the scales on an absolutely flat and solid surface (tiles, laminate, concrete).
- 🔹 Press the center of the platform with one foot to turn on the display, then remove the foot.
- 🔹 Wait until the value of 0.00 or 0.0 kg appears on the screen.
- 🔹 Do not touch the scales during 5-10 seconds after zero.
If you start on the scales immediately after zero, they may not have time to fix the baseline state and go back to standby mode or show an error. In some models, you need a short press on the hidden reset button on the bottom panel, but for most modern versions of the Mi Body Composition Scale, software initialization through on is enough.
Connection and synchronization problems
Sometimes the "L" error can indirectly affect the balance's ability to connect to a smartphone. At low voltage, the Bluetooth module is unstable: it may not be detected by the Mi Fit or Zepp Life application, or the connection may break during the data transfer. If you see the low-charge code, synchronization attempts are likely to fail.
In rare cases, users are faced with a situation where the batteries are new, the "L" error is gone, but the scales are not visible in the application. This may require a complete reset of the pairing mode. This usually requires removing the batteries for 1-2 minutes and then inserting them back, which force the Bluetooth microcontroller to reset.
⚠️ Note: If the scales stopped syncing after updating the smartphone operating system, try removing the device from the Bluetooth list in the phone settings and re-add it through the app.
Older versions of Mi Fit may not work properly with new firmware scales. Make sure your smartphone has the latest version of Zepp Life (formerly Mi Fit) installed as Xiaomi is gradually migrating users to the new platform.