I reverse engineered a ThinkPad Battery - and made a perfect clone

The IBM ThinkPad 701C is an iconic laptop. I go through every step to build a brand new battery. From modeling and printing a new case, label, building a new battery pack, recreating the terminal PCB and most importantly, cloning a once proprietary chip using an ATtiny microcontroller.

All of the designs, code and instructions can be found at my site: https://701c.org and on Github at: https://github.com/hrushka/701c.org

I've included timestamps below to help navigate, but I hope you enjoy this dive into a multi-skill build.

Chapters:

0:00 - Introduction
1:09 - Cleaning and breaking down a 701C battery
4:32 - Shop Helper
4:40 - Modeling the case with Shapr3D
7:45 - Taking measurements for the terminal PCB
9:15 - Creating the debugger PCB with EasyEDA
10:13 - Assembling the debugger
12:30 - Testing the debugger with a known working Dallas DS2434
14:40 - Capturing data with a logic analyzer and Logic2
14:47 - Evaluating the data and stubbing out code
15:36 - Testing the cloned chip
16:15 - Designing the production PCB with EasyEDA
17:01 - Soldering 9 NiMH cells into a battery pack
19:18 - Recreating the label using Sketch
22:43 - Testing the labels for size and accuracy
23:14 - Printing the battery case with an Elegoo Saturn 2 8k
24:55 - Sanding and polishing the case using acrylic polish
26:10 - Testing & assembling the final chip and PCB
28:04 - Final assembly!
28:58 - The final test on a pristine IBM ThinkPad 701C
29:12 - Obligatory Doom cameo

The epic tunes:

Midnight Rider - The Big Letdown: https://www.epidemicsound.com/track/ZUMfW0Lu4Y/
Carbon - Truvio: https://www.epidemicsound.com/track/p6hn1aGkNF/
A Nebula Inside - ELFL: https://www.epidemicsound.com/track/nGcpOsyzpf/
Sunstorm - ELFL: https://www.epidemicsound.com/track/x5VhqQSb5f/
Inevitable You - Amaranth Cove: https://www.epidemicsound.com/track/yd4H4JBBGH/
Games in Color - Emil Axelsson: https://www.epidemicsound.com/track/cUkhnyVs1d/
Is This Love a Waiting Game - The Big Letdown: https://www.epidemicsound.com/track/6G7Eipbbo1/
Divergent - Ooyy: https://www.epidemicsound.com/track/wVYSNAgyuQ/
Don't Lock Your Love Down - Kadent: https://www.epidemicsound.com/track/LwlAasraGI/

Music:
All music licensed by Epidemic Sound