Update - after a busy week of analysis I have a PCB design in the works that is a drop in replacement for the BMB PCBs to allow a bricked pack to be safely trickle charged in car (or out of car).
The Roadster has 99 bricks in series - the design is basically 99 fully-isolated charging circuits with communication back to a PC for monitoring.
If a brick is very low the charging starts at 20mA so shorted bricks can be auto-detected (20mA max through a shorted cell). Once it has been determined the brick isn't shorted it is charged at 100mA (still very slow). Each brick is individually voltage and current controlled so no risk of cell over-voltage like you have with putting voltage across a sheet or the pack.
Use 1 - if you have removed a pack from a damaged car this system is a way to safely keep the pack charged.
Use 2 - if a pack is bricked this system will tell you the voltages of all 99 bricks in car so you know the health. If it is just a little under voltage you can likely unbrick the pack without removing it from the car. Once charged enough the car can take over normal charging duties.
Use 3 - if a pack has shorted cells this system will keep the other bricks charged so you don't lose the other bricks.
I will have boards back from fab next month.
If there is interest I will create a Kickstarter to build more of them.
The Roadster has 99 bricks in series - the design is basically 99 fully-isolated charging circuits with communication back to a PC for monitoring.
If a brick is very low the charging starts at 20mA so shorted bricks can be auto-detected (20mA max through a shorted cell). Once it has been determined the brick isn't shorted it is charged at 100mA (still very slow). Each brick is individually voltage and current controlled so no risk of cell over-voltage like you have with putting voltage across a sheet or the pack.
Use 1 - if you have removed a pack from a damaged car this system is a way to safely keep the pack charged.
Use 2 - if a pack is bricked this system will tell you the voltages of all 99 bricks in car so you know the health. If it is just a little under voltage you can likely unbrick the pack without removing it from the car. Once charged enough the car can take over normal charging duties.
Use 3 - if a pack has shorted cells this system will keep the other bricks charged so you don't lose the other bricks.
I will have boards back from fab next month.
If there is interest I will create a Kickstarter to build more of them.