PinePhone Battery Charger
I recently picked up this little battery charger made specifically for the Samsung J7 battery used by the PinePhone (Pro). It features:
- A single USB-C port
- Red/green status LEDs
Yeah that’s about it. Very simple, but that’s good.
Seems to work just fine, but for shits and giggles I decided to break it open. I figured maybe this could be useful to someone making their own charger.
For lack of better photos, here’s the original product picture from Pine64:
This is the very simple PCB inside. It’s based around the MICRONE ME4057DSPG-N IC.
Here is a (somewhat poorly) translated copy of the datasheet.
The charging logic for this IC is as follows:
- Under 2.9V, trickle charge at 1/10 IBAT
- CC to 4.35V
- CV at 4.35 until current falls to 1/10 IBAT
- Off, showing (Green) STBY LED
- If voltage drops to 4.16V, charging is resumed from the CC stage
From the datasheet, IBAT = 1100/RPROG, meaning the battery charging current is approx. 790mA or 0.26C of the original 3000mAh battery that comes with the PinePhone (Pro), and trickle & cutoff current is about 79mA.