ADC Calculator

Understanding the Two Calculators

Meshtastic devices often do not charge batteries to the true chemistry maximum of 4.20V. Some boards reach a lower maximum (for example 4.15V), which causes the displayed battery percentage or voltage to appear incorrect.

This page provides two ways to correct this behavior:

100% Battery Display Calculator — Adjusts the ADC multiplier so the device shows 100% when your battery reaches its actual full voltage, even if that voltage is below 4.20V.
Accurate Voltage Calibration Calculator — Adjusts the ADC multiplier so the displayed voltage matches a multimeter, giving true electrical accuracy.

Choose the calculator that matches your goal.

100% Battery Display Calculator

Makes Meshtastic show 100% at your board’s actual max charge voltage

Use this calculator if your device never reaches 4.20V but you want the battery indicator to show 100% at the voltage your board actually charges to.

Device:
Battery Voltage (V):
Current ADC Multiplier:
Calculated New Operative ADC Multiplier:

Accurate Voltage Calibration Calculator

Makes the displayed voltage match your multimeter

Use this calculator if you want accurate voltage readings, even if the battery percentage ends up lower than 100%.

Device:
Max Charge Voltage (Multimeter):
Displayed Voltage (Device):
Current ADC Multiplier:
Adjusted ADC Multiplier: