Here are some handy mathematical formulas to help you figure out what those waveforms mean, and how to convert them to other measurements, when you're measuring voltage in your batteries or other electronic devices.

Sine or square wave VPEAK-TO-PEAK = 2 × VPEAK
Sine wave VRMS = 0.707 × VPEAK, VPEAK = 1.414 × VRMS
Square wave VRMS = VPEAK
Power to decibels dB = 10 log10 (Power 1 / Power 2)
Voltage to decibels dB = 20 log10 (Voltage 1 / Voltage 2)
Decibels to power Power 1 = Power 2 × antilog10 (dB / 10)
Decibels to voltage Voltage 1 = Voltage 2 × antilog10 (dB / 20)