Charging battery packanually with variable power supply

[UserID Adam]

Hey everyone, new guy here.ooking for some advice on fixing my electronic paperweight(21' m3sr+).It was an auction car and has never moved an inch under its own power. As of now it has 51% soc but when I test the two battery haves one is 179v and one is 178v. I am trying to manually charge the brick to get both to 179v to be equal in holes this will remove an error code for pack mismatch. That said my question is what power supply should I use and do I just hook It up with neg on pyro fuse and positive on right post since I'm only charging half the pack.

 

[bwilson4web]

So thoughts:

Check parallel cell groups first - survey the parallel groups to make sure one is not a problem. At a nominal 3.2 VDC, they are much easier to deal with.

The 178-179 VDC range is not that high. I have no specific product recommendations so I would start with a general Google search. Alternatively, a power, switching buck regular power supply would not be that hard. Check with Texas Instruments for design papers.

Bob Wilson

 

[UserID Adam]

The problem I have is there are 4 packs inside the model 3 however only 2 of them (outside ones with BMS) have connectors to test. So technically your testing to pack together they way the drawing is shown. That said I can't narrow down which one has a weak link or is lower. I'm not sure if I could use a simple 12v charger to trickle it up or maybe that sounds like a stupid idea. Though I really only need 1 volt to get the banks to match. Sorry for ignorance