TI-55 Calculator

TI-55 Calculator Battery Replacement


How I made my TI-55 calculator work. THE THING HAS AN LED BUBBLE DISPLAY.

Want to breath new life into an old calculator? The TI-55 was one of the best in the line of scientific calculators with statistical capabilities back in the 70’s.

The TI-55 has an LED-stick using LED chips mounted and bonded to the printed circuit board, and has some 12-digits instead of the 9-digits of other calculators from the same time period.

The TI-55 calculator used a rechargeable battery pack rather than using a 9V battery, so when the rechargeable no longer worked, your battery was dead. However, the voltage and current used in the rechargeable works out to be still, 9V capable, so this video shows how one can easily adapt the TI-55 for use with a standard 9V battery.