Description
Backorders ship in 2-4 weeks.
Got some really tiny 30 mAh LiPos and are all of your chargers 100 mA or more? Treat those little lithium polymers with kid gloves with our Tiny Lipo Charger Kit! These little boards are set to charge at a wee 10 mA max, and if you swap out the PROG resistor, you can set it to charge at any current from 3 mA to 600 mA! What's even cooler about this chip is that it has built-in undervoltage/overdischarge protection, so it can even be used in a project with unprotected lil' LiPos or supercapacitors! The battery discharge output is fully isolated from the battery input, so this chip has some cool protections that most chargers don't.
Nice Features:
- Breadboard-compatible, battery output plugs right into a power rail
- There are 2 headers for the power rail spaced 0.6" apart - plug both in and have a super stable board that overhangs your breadboard or plug only the bottom one into the corner of your breadboard for minimal hole occlusion.
- Convenient JST-PH 2-pin connector for the battery
- Works with any USB-C or USB-A power supply (onboard CC resistors)
- Very tiny and cute (18 x 20.5mm)
Specs:
- 10 mA charge current: changeable by swapping out resistor (friendly 0805 size)
- 1.2A discharge current: max continuous at any battery voltage level, or limited by your battery capacity for tiny LiPos
- Battery reverse polarity protection: if the battery is hooked up backwards, nothing bad happens
- Output reverse polarity protection: the output is disconnected from the battery, no current is drawn, hiccups every 8 seconds
- Output overcurrent protection: same behavior as above when output current reaches 1.7A.
- Undervoltage protection: output is disabled when the battery voltage drops to under 2.8V.
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Overcharge protection: goes into constant-voltage charge mode just under 4.2V and terminates charging at 1 mA (or 10% charge current setpoint)
- Trickle charge mode: for batteries discharged to low voltage, it automatically trickle charges at 2 mA (or 20% charge current setpoint) until the output reaches 3.2V, then goes to the full charge current
- Thermal protection: chip disabled at 145C
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Soldering required: the 2-pin JST-PH connector and BATT+/- output headers. Both are optional, you can directly wire a battery and load to these holes. A + battery input pad is also provided on the top of the board and a - (GND) pad on the bottom of the board.
LED Indication:
- Solid: charging
- Off: fully charged, or no USB power & no battery
- Flashing: USB power present, no battery
- Dim: battery is connected backwards (reverse polarity)
Resistor Charge Current Setting:
These two equations were given in the datasheet, which aren't very accurate especially at low charge currents. R is in kohms and IBAT is in mA.
We've found their data and our own fit to an exponential decay curve very well, so at the risk of slightly more complicated math, we've found this equation to be an almost perfect match:
