I’m charging 2 LiIon cells with MP2672 with a typical 5V USB, but the current meter does not show any current.
For a 5V USB I measured:
| Column 1 | Column 2 |
|---|---|
| PIN | Voltage, V |
| IN pin 1 | 4.7 |
| SW pin 2 | 6.0 |
| BST pin 3 | 4.7 |
| MP_VCC pin 4 | 3.6 |
| VLIM pin 7 | 2.3 |
| NTC pin 8 | 1.8 |
| MID pin 9 | 4.0 |
| BAT pin 10 | 7.45 |
| SYS pin 11 | 7.7 |
| STAT pin 16 | 1.4 |
| CV pin 17 | 0.3 |
| ACOK pin 18 | 0.16 |
Pins 10 and 11 might be swapped in the table above, need to check.
When I increased the USB voltage to 5.4V, I saw 250mA current in my current meter.
I used the schematics I found somewhere and there VLIM was a simple voltage divider 1k/1k. So did I. Not sure if it’s correct though.
BALLANCE_EN is pulled low and controlled with an external GPIO I2C expander - I couldn’t come up with something smarter to
-
automatically charge on start when USB power rail is powered
-
allow the user to configure charge settings if they want to without any jumper (they don’t have access to the hardware)
P.S. I looked at similar topics here but didn’t find the answer.
