Bafang Battery Charge Port: Mechanical Simulator

Rather than poke things into the undamaged charge port of our battery, I built a quick-and-dirty mechanical duplicate:

Bafang battery - charge port simulator
Bafang battery – charge port simulator

The “center pin” is a snippet of what’s almost certainly 5/64 inch brass tube measuring Close Enough™ to 2.1 mm, with a few millimeters of 3/32 inch tube soldered on the end to simulate the nugget.

The aluminum rod has a 5.5 mm hole matching the coaxial jack’s diameter and depth, with a smaller through hole for the “pin” and a dab of Loctite bushing adhesive.

Then I turned the end of a 3/8 inch acetal rod down to a 5.5 mm bushing that completely fills the jack:

Bafang battery - guide bushing - dummy jack
Bafang battery – guide bushing – dummy jack

It has a 3 mm hole down the middle to aim homebrew shell drills directly at the pin, while preventing a short to the side contact.

The first test looked encouraging:

Bafang battery - shell drill - test results
Bafang battery – shell drill – test results

The nugget in the damaged jack is definitely larger than my soldered brass tube, but this was in the nature of exploratory tinkering while mulling the problem.