DIY Electric Car Forums banner

Chevy Volt cell checker

1004 Views 2 Replies 2 Participants Last post by  Dan Hawkins
This is an amateur design for quickly checking individual cell voltages in a Volt Gen II battery pack. It requires that your battery blocks have remained whole in their original groupings of 12 or 16 cells (more correctly, 24 or 32 cells, because a "cell" is a parallel pair). It also requires that you can access the top of the battery to plug into the 18-pin sockets that peek through the flat plastic top cover. The plug you use is one of those that attach to the Volt's BMS, just pick one with a long enough wire bundle to reach all your battery groups. Cut the wires somewhere before they reach the BMS. Expect to unwind a lot of orange tape to isolate one plug and its wires. Be sure you pick one with 17 wires, not 13.

The voltage checker is a hand held box with 16 pushbutton switches. It has two pin jacks where you can plug in the leads from your multimeter. You push the corresponding button for each cell and read the voltage. The box can be any enclosure with sufficient space. I'm using the Volt's own BMS box, without the circuit board. Note the strip of fuses - do not omit unless you like fire and smoke, because pushing two buttons at the same time is a dead short.

If you see an egregious error in the attached drawing, please let me know. I have not built this thing yet, and I would prefer to try it out without smoke!


1 - 3 of 3 Posts

· Registered
33 Posts
Discussion Starter · #3 ·
Thanks, Duncan. I had in fact seen that post some time back, and appreciate its ingenuity. But when I got to tracing out the wiring on the Gen II, I lost confidence that the plug on the BMS end indicated the cells that I thought it should. I had some "WTF" moments while stripping off that orange tape. Maybe I gave up too early. Since I've already bought the bits and pieces, I will go ahead and put the thing together.

1 - 3 of 3 Posts
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.