The purpose of this project is to have a rechargeable battery intended to be inside an enclosure for various synthesizer designs, however, it can be utilized for any purpose.
The motivation for this project was that I have not found an adequate solution. There are a number of current solutions available, but the following limitations create issues for the overall design.
- Soldered on USB charging ports
- Soldered on power switch
- Soldered on power, charging and charge LEDs
Due to the above, they do not suite the usage inside of a project enclosure without desoldering these components and attaching wires in their place for panel mount switches, power and LEDs.
I have, however, found one solution that satisfied the above issues. Unfortunately, these devices produced audible frequencies that prevented it being functional as a power supply for a sythesizer.
Due to the above conditions, I reached out to work with an engineer to help create the schematic and PCB layout for this purpose.
The devise is intended to be used with 2 18650 batteries. The JST connectors are provided to hook up the components such as the DC Barrel Jack for charging, 5v output for the device, Power switch and LEDs for Power, Charging and Charged status indicators.
The power supply should be 5v2a (or 5v3a). Output is 5v1a.
I had the device manufactured at https://jlcpcb.com of which all components are normal stock items.
The current solution does not provide protection for low or short battery (perhaps this will be modified in a future version).
The status light output of the CN3302 IC is a little vague in it’s output as both lights appear to be on during charging.