EKM001 - Battery Charger LiPo 3.7V 0.2-2A
Part.no: 41021046
EKM001 is a compact charger for single cell LiPo batteries with an integrated protection circuit (4.2V charge voltage). The charger has an adjustable charge current in fixed steps from 200mA to 2A. The charge current is selected by connecting or disconnecting the four jumpers on the back of the board. Which configuration suits a given battery depends on the maximum allowed charge current indicated by the letter "C". EKM001 is preconfigured for the lowest charge current, 200mA, to avoid the risk of charging with excessive current.
Under normal use, a power source is connected to the USB-C port and the battery to the white JST PH connector at the other end. There are also connection points for an alternative power source (4.1 – 6.2VDC), a 3 pin connection for batteries with a built in NTC resistor* and an output for powering a device while the battery is charging. An LED on the board indicates the charger status (off = battery fully charged, on = charging, flashing = charging error). All connections (IN, OUT, BAT NTC) have a 2.54mm pitch and are compatible with standard pin/socket headers, screw terminals, Molex KK or MTA 100.
Please note that the output will have different voltages when battery powered (3.7V nom.) and charging (5V).
*If the charger is used with 3-pin batteries with built-in NTC resistor, the user must replace the two resistors R1 and R2 (SMD 0805). Se the BQ25302 datasheet for mor information
Functions
- High efficiency switching design
- Separate load output with automatic switching between charging and operation (Power Path)
- Connection for 3 pin LiPo batteries with built in NTC resistor*
- Charging via USB C connector or any 5V source
- Selectable charge current from 0.2 to 2.0A
Specifications
- Supply voltage: 4.1 – 6.2V
- Switching frequency: 1.2MHz
- Efficiency: ~94%
- Charge voltage: 4.2V
- Safety features: temperature, under/overvoltage, overcharge
- Charge current: 0.2A, 0.4A, 0.6A, 0.8A, 1.0A, 1.2A, 1.6A, 1.8A, 2.0A
- Dimensions: 35 x 20mm
- Mounting holes 4x ø2.54mm / c-c 30 x 15mm
Connections
IN: Connection for an alternative power source 4.1 – 6.2VDC. Directly connected to VBUS. Do NOT apply voltage to the USB port when this input is used. It is however fine to draw 5V when the board is powered through the USB port.
OUT: This is where the powered device is connected. Note that the output voltage differs during battery operation (3.7V) compared to battery charging (5V). Maximum current draw is approx 2A.
NTC: Connection for batteries with a built in NTC resistor. The resistors R1 and R2 on the board normally define the temperature range and are populated with 10kohm. If a battery with an NTC resistor is to be used, these resistors must be replaced (page 16 of the BQ25302 datasheet).
Charge current: Jumpers used to set the maximum charge current for the connected battery. The board is delivered with jumper A closed and B, C and D open, which gives a charge current of 0.2A. By shorting the different jumpers the charger can be configured to charge at higher current.
Examples:
1.2A: short B and C
1.6A: open A, short C and D.
The connectors on the board fit several different connector types with 2.54mm pitch, such as standard pin headers, Molex KK connectors or screw terminals.
All connectors on the board are placed on a 2.54mm grid, which means that with pin headers mounted the module can easily be used in both breadboards and all of our prototyping boards.
Mechanical dimensions
