A probe to measure temperature using an oscilloscope.
You got to measure the Amps.
A compact, headless, 62.5MS/s, 7.5MHz bandwidth oscilloscope.
A system to charge batteries with an engine.
This is my homebrew multimeter design. Included modes are VDC, Ohms, and Capacitance.
This is a basic curve tracer that sends data to a computer to be plotted.
This is a system that charges, balances, and handles the output of 5 18650 batteries. It is also software controlled and customizable.
A simple bright rechargeable flashlight.