Sony MZ-EH50/70 Battery Sidecar

MZ-EH50/70 Battery Sidecar

A battery sidecar for the MZ-EH50/70 mindisc player. Device functions similar to OEM sidecars, with the intent to use this design as the basis for other sidecar builds. The build uses the following:

• 2xM2x10mm screws

• 1x M2x3mm insert

• 6x M1.7x 6mm screws

• Battery Terminal clips (aliexpress)

• Copper Tape (3mm wide, cut to fit)

• 2x 5.5mm long Pogo Pin with 1.5mm center (and 2mm base) (aliexpress)

• 1.5mm drill bit

How to Assemble

1) Preliminary Items, the adapter plate should be printer with supports, everything else can be printed with out supports. Remove all supports, and drill out the pogo pin holes with a 1.5mm drill bit. Fit check all parts, as the adapter plate must be flat to the battery body. Insert M2 inert into thumbwheel...and make sure it is straight, secure M2 bolt with a drop of superglue.
2) Apply copper tape to the tracks as shown in the pictures; the + side track should go fully through to the + terminal. I found it easiest to thread the tape with the backing on, cut to length, remove the backing, and set into the groove on the back side (where the adapter plate connects). Once the tape is in place, jam the terminal lugs into their respective holes. The - side will be exposed to the adapter plate; bend the lug to the copper tape. On the + side, it is a contact fit...push hard to get the lug fully into the hole! Insert a battery to set the contacts into their locations.
3) Verify voltage at the copper tape.
4) Assemble with thumbwheel, and verify voltage at pogo pins. If none, add a pad of copper tape to the cylinder that interfaces to the pogo pin and check again.
5) Add 4 screws to the back of the plate and 2 to the hinge, and enjoy.

Last note on minidisc batteries: give these AA from Kratax a look, Lithium Ion that deliver 1.55V until they need to be recharged.