WM220 Battery Intelligent Board
Function
Variants
Parts
Programming
External interfaces
Service interfaces
Board view
Schematics
DJI Intelligent Flight Battery for Mavic is a 3830mAh, 11.4V LiPo-3s battery, supporting up to 27 minutes of flight time. The battery also has built-in sensors and bright LEDs that let you know the status and remaining power. It contains automatic discharge feature to avoid swelling (fully charged LiPo cells release hydrogen), and Permanent Failure feature which disables the battery in case of damage or unexpected behavior of cells.
The battery management system chip (TI BQ30Z55) is queried for data by a small micro-controller (TI MSP430) through a Smart Battery System protocol. That micro-controller sends updates to the FC in regard to current battery status, through UART interface.
The SBS protocol defines battery-related commands to be transferred over SMBus, which in turn is devised from I2C.
There are multiple versions of the board.
| Marking | Overview |
|---|---|
| P01690.06 |
| Marking | Amt. | Pkg. | Function | Specification |
|---|---|---|---|---|
| BQ30Z55 6CT G4 AQGF | 1 | TSSOP-30 | Integrated 2-Series, 3-Series, and 4-Series Li-Ion or Li-Polymer Cell Battery Pack Manager and Protection; the specific chip was only made available by TI for a few customers, but it is very similar to BQ30Z554. Also, its spec can be found in various places (sluu852a.pdf). | description applc.note |
| 1C530l Prm 1708 C1 9632 | 4 | Nexperia N-channel 30V 1.55mOhm logic level MOSFET in LFPAK using NextPower technology | description | |
| MSP430 G2755 TI A66K CF0Q G4 | 1 | MSP430 ultra-low-power sensing and measurement MCU | description | |
| WM9 71 | 2 | SOT23 | ||
| VS6 Z | 1 | SOT23 | ||
| K7K DN | 5 | SOT23 | ||
| 14D | 1 | SOT25 | ||
| R004 | 2 | SMD Resistors | ||
| 101 | 2 | SMD Resistors | ||
| 201 | 3 | SMD Resistors | ||
| 330 | 8 | SMD Resistors | ||
| T4 | 3 | |||
| AC | 7 |
| Chips | Firmware | Description |
|---|---|---|
| BQ30Z55 | Battery control chip; it has firmware, but that is not publicly available. | |
| MSP430 | Small micro-controller which queries the BQ30Z55 for battery status and sends the information to Flight Controller. |
Connectors on the board are:
| Marking | Overview |
|---|---|
| 10-slab EXT PWR | External connector of the battery; provides power input and output, and serial interface. |
Here is the connector pinout:
| Pin | Label | Function |
|---|---|---|
| 1 | RXD | UART receive |
| 2 | PACK- | Ground reference for PACK+ |
| 3 | PACK- | |
| 4 | PACK+ | +12.92V from battery cells |
| 5 | PACK+ | |
| 6 | PACK+ | |
| 7 | PACK+ | |
| 8 | PACK- | |
| 9 | PACK- | |
| 10 | TXD | UART transmit |
The following service pads exist on this board:
| Marking | Overview |
|---|---|
| TODO |
Top of a P01690.06 board:
Bottom of the P01690.06 board:
Top of another P01690.06 board:
Bottom of the P01690.06 board:
No schematics available.