Teardown

Xiaomi Mi Power Bank 3 Pro Teardown (20000mAh 45W)

The Xiaomi Mi Power Bank 3 Pro is Xiaomi’s third generation of power bank. This power bank supports two USB-A and one bi-directional USB Type-C fast charging protocols. Let’s begin to dismantle it to see its internal structure.
remove the faceplate
First of all, use an insulated pry to remove the plastic faceplate of the output end. The double-sided tape can be found on the back of the cover.
remove the plate at the bottom
Now take out the blocking plate at the bottom. The plate uses double tape as well. With the plate removed, four screws which secure the blocking plate to the bottom can be seen. Take out the screws.
remove the screws
Once the screws are removed, the whole unit can slide out of the channel chassis. At present, most chargers adopt this design. There are four indicators which show battery power.
middle frame
This is the internal middle frame. A graphite ticker is on the left.
the other side of the middle frame
Look at the other side of the middle frame. There are three graphite stickers.
uncover the sticker
Uncover the sticker, and the PCBA unfolds. The luminous transparent module is universally called a light pipe. This component works with the LED indicator.
two screws
Two screws are placed under the graphite sticker.
middle frame
The internal middle frame is composed of two parts: top faceplate and bottom faceplate.
roller cage
The middle frame consists of a roller cage. With other small components, this frame is more stable and shock resistant. When deciding the position of PCAB, the designer has taken a circuit layout into consideration.
middle frame material
The middle frame is made of PC and ABS.
battery
The battery resides in the middle frame by the black sponge tape. These are the specifications of the battery module. Its model number is PLM07ZM; its rated voltage is 7.4V; its limited charging voltage is 8.7V; its manufacturer is ZMI.
remove the battery
Separate the battery from the middle frame. We can see some information on the other side of the batter.
cell
The cell is provided by ATL. The ATL lithium polymer pack is made of two cells in parallel.
NTC pack thermistor
The NTC pack thermistor is provided for thermal protection of the pack.
electrical inductors
The PCB comes with two electrical inductors.
PCBA
It’s the back of the PCBA. The big inductor is manufactured by CETC.
FP6601Q
The module labeled as FT4yJA is the Fitipower FP6601Q- a fast charge protocol controller for Hisilicon Fast Charging Protocol(FCP) and Qualcomm Quick Charge 2.0/3.0 USB interface.
information on the FP6601Q
It’s the information on the FP6601Q.
the SGM7227
This is the USB-C controller which supports USB PD handshake. The module labeled as 27X is the SGM7227 switch from SG Micro Corporation. It is compatible with high-speed USB 2.0.
battery protection IC
The module labeled as 3HB5 is the battery protection IC.
8205S
The 8205S is the output switch. Its circuit board adopts multiple processes which are good for its heat dissipation.
Vanguard’s VS 3618AP switch
It’s Vanguard’s VS 3618AP switch.
USB-A port
This is the USB-A port.
front of the PCBA
It’s the front of the PCBA.
TR5611 SCM
This is the TR5611 SCM.
Joulwatt JW3651 converter
Joulwatt JW3651 converter is responsible for USB-A port fast charging output. It is an integrated four-switch buck-boost converter.
Intersil’s ISL9238
Intersil’s ISL9238 is a buck-boost Narrow Voltage DC(NVDC) charger.
ISL9238
In Charging mode, the ISL9238 takes input power from a wide range of DC power sources (conventional AC/DC charger adapters, USB PD ports, travel adapters, etc.) and safely charge battery packs with up to 4-series cell Li-ion batteries. It provides the NVDC charging, system bus regulation and protection features for tablet, Ultrabook, notebook, power bank, and any USB-C interface platform.
all the components
These are all the components of the Xiaomi Mi Power Bank 3 Pro.

Summary
We find that the Mi Power Bank 3 Pro version has made many breakthroughs on its circuit. For instance, it features Renesas ISL9238, Joulwatt JW3651 two buck-boost chips. Besides, the charger adopts TI BQ29200 battery voltage equalization chip. In general, the Xiaomi Mi Power Bank 3 Pro has excellent workmanship and adopts high-quality materials. One of the charger’s highlights is that its middle frame applies multiple roll cages.

Source
chongdiantou

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