For some time now I have been looking for an open source USB-C Powerbank. I didn't find it so I started my first project.
Preliminary characteristics:
- 1 quality USB-C connector
- USB Power Delivery 3.0 dual role
- Certified integrated solution
- Source, 5 to 20V, max 45W
- Sink, 5 to 20V
- Li-ion charger
- Buck / Boost
- Programmable
- Rated charging current, 1.5A
- For 4 cells (4S)
- BMS
- Programmable
- Smart fuel gauge (battery health)
- All protections (Under Over Temp, Under Over Voltage, Short-Circuit)
- Cell balancing
- Management by microcontroller
- Low power
- I2C / SMBus hardware
- Maybe integrated into the Power Delivery Controller
- Possibility to use the battery voltage (Vbatt) to power external projects.
- 4x quality 18650 cells
- Open Hardware Licence CERN-OHL-W (weakly reciprocal)
Preliminary synoptic:
Hi Kosma. I am not a battery specialist but integrated cell balancing circuits can only handle small differences.
Maybe you can create a battery pack with the old cells and a pack with the new ones and create an automatic battery selector.