I need to power a Bluetooth speaker (Beatbox Portable) with a battery pack while also allowing DC power in.
I also want to use the input DC power to charge the four cell lithoum ion battery pack.
Can I use buck and boost converters as in the circuit below?
D1 and D2 are safety diodes to prevent current from flowing in the opposite direction.
The below image is a 2nd option that I'm still trying to achieve. I am not sure if I will be able to as the space inside the speaker is limited.
Other side questions:
- What happens if the BMS is triggered due to a short circuit or low battery voltage?
- Will connecting the main DC input (18.5V) reset the BMS?
- Is it OK to leave the BMS connected to the load?
- Can this charger board work for five cells in this application?
I'm still in the concept and testing phase. I haven't chosen any component yet, but I was looking at the XL6009 buck+boost converters.
Here is the DC power supply:
Another Potential Solutions:
1- Using this USB-C charging board for 4S or 5S cells with a manual switch to select between DC input or battery pack.