Working on implementing the diybms to manage a 25kwh battery pack I’ve installed in my 5th wheel RV. The battery utilizes 4 Tesla Model S battery modules (6s/250AH) in parallel, each with a 1s/250AH (74 18650 cells) to keep my 24v inverters happy. I built this system over the course of 2 years adding 1 module at a time as I could afford to build it out. In hindsight I wish I had started with a 14s system (51.8). What I would have saved in copper wire expenses would be well worth it.