AED 37.80
Description
According to the product designers, this module board Can power a mini PC Raspberry Pi. In theory, it can power any Raspberry Pi or any other mini PCs (Orange Pi, Banana Pi, Odroid …) that have a USB OTG port. Be careful however to buy a high capacity LiFePO battery. The card has no output to measure the battery charge level. It will, therefore, be necessary to measure the complete time to full charge to avoid any sudden stop of your system. Also, be careful to stop the system before turning off the power using a microswitch on the shield. because it will Raspberry Pi immediately.
The shield has a fairly basic charge control circuit. you need to be aware of the polarity. Any change of polarity may cause the burning of the charging circuit. The board has a micro USB connector to charge the battery.
We can power any development card or any device which has a USB port. For this, we have a type-A USB output. The maximum power delivered is not indicated. It is nearly 4A as the side connectors. We also have 3 connectors to deliver 3V up to 1A and 3 connectors to deliver 5V up to 2A. The 6 connectors are on each side of the board. It will directly solder the power supply or solder a header at a pitch of 2.54mm beforehand.
18650 LiFePO4 Battery Shield Technical data
- Power supply: 5 to 8V via micro USB port up to 0.5A
- Output power
- 5V via USB Type-A port
- 3 connectors to deliver 3V up to 1A
- 3 connectors to deliver 5V up to 4A
- Misc: 1 USB output, LED for the state of charge (green = battery charged, red = charging)
- Battery protection (overcharging or over-discharging). Attention, no protection in case of reverse polarity
- Dimensions: 98 x 29 mm
A quick breakdown into key components
The background electronics are a clever blend of three requisite circuits, that is to say, a lithium-ion battery charger circuitry, a battery protection circuitry, and a dc-dc boost converter circuitry. Refer to the annotated image provided below (and the table next to it) to get a deep insight into the underlying electronics.
COMPONENT | DESCRIPTION |
U9 = DW01V | 1S Li-Ion battery protection chip |
F1 = 8205A | Dual N-Channel MOSFET |
U2 = TC4056A | 1S Li-Ion battery charger chip |
U7 = FP6298 | 4.5A current mode dc-dc boost converter chip |
U4,U5,U6 = 662K (XC6206xxxx) | Positive voltage regulator chip (3.3V) |
L1 = Green LED | Battery CHGD indicator |
L2 = Red LED | Battery CHRG indicator |
S1,S2,S4 = Schottky Diodes | S1 = SS14 & S2,S4 = SS24 |
the circuitry of the Li-Ion battery charger chip used in the 18650 battery shield strictly follows the typical TC4056A application circuit except for a minor change in the value of the battery charge current limiter resistor (RPROG). In this shield, it’s a 2KΩ resistor that results in a maximum charge current of 600mA +/- 10%.
Similarly, the FP6298 circuitry is a replica of its typical application circuit but with a minor deviation in the value of the overcurrent protection (OCP) and feedback (FB) network resistors. Here the OCP value is about 3.7A and the final output voltage is 4.99VDC.