The Tektronix 222 and variants such as the 224 were sold originally with a sealed lead-acid (SLA) battery. Replacements for these SLA batteries stopped being manufactured a long time ago and, due to the form factor of the original battery, there are very few available SLA batteries that can be made to fit in the scope.
This kit allows the use of up to three readily available 18650 rechargeable lithium batteries to replace the now unavailable SLA battery. No modifications to the scope are required other than removal of the original SLA battery. Charging and protection circuitry is provided, allowing the use of unprotected 18650 cells. The kit consists of one assembled and tested battery charger circuit board, one 3D printed case, and some miscellaneous parts such as light pipes to bring the LED indicators to the front of the case and a jumper cable to attach to the scope’s battery connector. The kit does not include rechargeable 18650 lithium batteries (required for operation).
Attributions and more information
Circuit board design based upon the work of Kitsune-Denshi. licensed under the Creative Commons Attribution-ShareAlike License.