My Opus BT-C3100 smells like magic smoke and looks like this. I suppose I could change these resistors and it might be OK, but I could also buy things.
I鈥檓 looking for 2-4 slots; it should fit protected 21700s; it shouldn鈥檛 have a noisy fan that runs all the time like the Opus; USB-C input is preferred, but not required.
I鈥檓 broadly aware of what鈥檚 on the market, but I want to know if you love or hate yours.
You know this, but I鈥檒l say it anyway. Discharging = heat and an implementation with no fan will probably result in shorter component life. Granted, someon else could use a quieter fan or a heat sync big enough to not necessitate active cooling.
If you鈥檙e feeling adventurous, up size those resistors with through hole variety and offset them from the PCB so they get a bit more airflow.
Let us know what you end up with!
This design has pretty poor airflow and a small, loud fan. I鈥檓 OK with a fan if it鈥檚 less obnoxious than this one. I鈥檓 also OK with a bit shorter component life; I got over ten years out of this one.