fischertechnik battery stick update

The outdated fischertechnik battery stick can be turned into a state of the art accu and power bank. The original idea came from Jan Hanson (juh) who posted a version on the ftcommunity forum in 2018. However his version did not use 3D printing.

There are different battery stick versions; the lids presented here are for the stick where the upper lid below the switch can be removed. There are two types of nobs with which the lid can be shifted in the bottom half (type a and b, use a for the stick where there are no obstructions in the lower part, b for the type with obstructions)

These versions uses customised lids for two of the various versions of the battery stick and are designed for either 5V or 9V

The 9V version consists of two 18650 cells, a 2S BMS, a MT3608 dc/dc boost converter, a 2S capacity meter and a mini voltmeter, plus a 2-channel on-off switch and a 9-12V dc female connector.

The 5V version has one 18650 cell, a 1S BMS, a LM2596 dc/dc boost converter, a 1S capacity