Diy BMS cell module, a variation of Stuart Pittaway`s design, full THT with opto isolators instead of transformer type isolators for I2C

I`ve been interested in energy harvesting and storing some time ago and when it came to new battery chemistry a management system was needed. I did find and buy some of these passive dumb bms on Ali, but near real-time monitoring came with a price and a closed proprietary software. Then some time later on youtube I found a bms designed by Stuart Pittaway. I found it`s properties good enough and decided to make a few with my own pcb design. Also there was the issue of not so cheap I2C ADUM transformer type isolators, that made me hesitate. So I searched for an alternate way to galvanically isolate the I2C bus. I found an application note, where the authors used 6N137/HCPL2630 optical isolators for just this purpose. I then incorporated their design into the bms cell schematic, added a DC to DC isolated brick for power and this board came to be. But also I haven`t tested the design myself yet so this will be a hit or miss. Also this is my first ever pcb not made by my own hands. It`s been over a year since I started this project and Stuart has moved on with his bms to version 4, which now also uses opto isolators and a different bus for comunication, so my design is a bit obsolete by now.