I found this cool little voltage monitor that just plugs into the balance tap on the pack while your running and it monitors each cell induvidually. If one of the lights turns red then that cell is below the cutoff voltage even if the pack as a whole is still ok. Seems like a simple and nifty little safety measure for only a couple bucks. I just ordered a couple to try out and see how they work.
https://www.unitedhobbies.com/UNITED...idProduct=4175
Anyone ever tried these or something like it?