Fix DJI Battery: Drone Repair with DJI Battery Killer & CP2112

Introduction

Welcome to our guide on fixing battery issues with DJI drones. If you’re facing problems like your battery not charging, overheating, or needing firmware updates, we’ve got you covered. From Mavic Mini to Inspire 1 and Phantom, we’ll provide practical solutions and DIY tips. Learn about battery storage, maintenance, and specific fixes for different drone models. Get ready to optimize and upgrade your drone’s battery performance and enjoy hassle-free flights.

In this post, we’ll discuss a software solution for dealing with BMS (Battery Management System) issues by raising power failure flags, also known as flags. When a power failure is detected, the BMS shuts down to protect the battery. This can happen if the power drops below a certain limit or if you disconnect the cells.

We will walk you through an easy and effective drone repair method using the DJI Battery Killer and CP2112 Adaptor.

Say goodbye to battery charging problems, overheating, and more. Get your drone back in the air with this simple and effective repair method. Let’s get started on getting your drone back in the sky🛠️🔋🚀 Check out our previous post How To Build ESP8266 Flight Controller For Drone.

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DJI Drones Batteries

DJI drone batteries are considered intelligent Batteries because they have advanced features like a Battery Management System (BMS) that monitors key parameters like voltage, temperature, battery health, communication with the drone, safety mechanisms, hibernation mode, and optimized design.

These intelligent features enhance performance, enhance safety, and prolong battery life and longevity, providing a superior flying experience.

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DJI Mavic Air battery specs and pinout

DJI Mavic Air Battery Specifications

• Capacity: 3500 mAh
• Voltage: 11.55V
• Energy: 40.42 Wh (typical value)
• Battery Type: LiPo 3S
• Charging Voltage Limit: 13.2 V
• Discharge Temperature: -10° to 60 °C (14° to 140° F)
• Charge Temperature: 5° to 40 °C (23° to 113° F)
• Charging Time: Approximately 55 minutes (using a DJI charger)
• Weight: 140 grams
• Compatibility: Designed specifically for DJI Mavic Air drone

DJI Mavic Air battery Pinout

1. Positive Terminal (+)
2. Negative Terminal (-)
3. SDA (Serial Data)
4. SCL (Serial Clock)

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DJI Mavic Mini battery specs and Pinout

DJI Mavic Mini Battery Specifications:

• Model: BWX161-2250-7.7
• Nominal Capacity: 2250 mAh
• Battery Type: LiPo 2S
• Nominal Voltage: 7.7 V
• Charging Voltage Limit: 8.8 V
• Charging Temperature: 5 °C to 40 °C (41 °F to 104 °F)
• Maximum Charging Power: 29 W
• Applicable Model: DJI Mini 2S Drones

DJI Mavic Mini battery Pinout

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CP2112 Adaptor – USB TO I2C DEBUG BOARD 

The CP2112 Adaptor is a USB to I2C (Inter-Integrated Circuit) debugging board that serves as an interface between a USB-enabled computer and I2C devices. It acts as a bridge, allowing the USB host to communicate with I2C devices by using a USB-to-I2C data protocol.

CP2112 configures communication and host control between the computer and the target device, such as the DJI drone battery. By connecting the CP2112 Adaptor to a computer’s USB port, users can access and communicate with I2C devices, read and write data, and send commands.

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CP2112 Adaptor Pinout

1. VCC: Power supply voltage.
2. GND: Ground.
3. SDA: Serial Data Line
4. SCL: Serial Clock Line
5. WAK: Wake-up pin
6. INT: Interrupt pin
7. RESET: Reset Pin.

The CP2112 acts as an interface between your computer and the battery’s BMS. It communicates with the BMS via SDA and SCL connections. The BMS is designed as a safety feature to safeguard both the user and the battery in case of power failures, disconnections, or short circuits.

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Connecting Battery with CP2112 

To connect the interface to the battery, connect the ground pin of the interface chip to any negative terminal of the battery. Connect the SDA and SCL pins correspondingly to their respective points on the battery terminal.

To connect the CP2112 Adapter with a battery:

1. Identify the battery’s pinout.
2. Connect the GND pin of the CP2112 Adapter to the battery’s negative terminal.
3. Connect the SDA pin of the CP2112 Adapter to the SDA
4. Connect the SCL pin of the CP2112 Adapter to the SCL
5. Double-check all connections

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Download and setup DJI battery repair tool- Battery Killer

This program has been developed to unlock DJI Mavic batteries that feature bq9003 (bq40z307) chips, using the reliable CP2112 HID USB to SMBus/I2C adapter.

Revive Dead DJI Batteries Using DJI Battery Killer + CP2112

 

Download DJi_Battery_Killer

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Next, connect the USB interface to your Windows computer using a micro USB cable.

Open the software and click on “Connect.”

If it successfully connects and reads all the information, it means it’s communicating with the BMS.

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1. Click on the “Read Info” button to retrieve the battery information.

Now, you need to unseal the BMS and use the “pf2” function. This will make the battery operational again. The reset function’s exact purpose is uncertain, and I’m still waiting for clarification from the developer.

1. Click on the “Unseal” option to remove the seal on the battery.
2. Proceed to click on “Clear PF” to clear any power failure flags.
3. Next, click on “Clear PF2” to clear additional power failure flags.
4. Finally, click on “Reset Chip” to Reset the battery.

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Working

By following these steps, you can successfully unlock your DJI battery and resolve any related issues.

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