True Battery Capacity Tester Based on Arduino

Overview

The Arduino based capacity tester of true battery power is capable of measuring almost any type of rechargeable or non-rechargeable batteries by fully discharging the battery with known current and log data to PC.

Details

A full lab testing of batteries can be obtained by connecting the discharge circuit to Arduino. This can send the log data to the PC and be able to show a full graph or chart of the discharge and total capacity. Different batteries can drain different sources during various discharge phases. Sometimes, at the end of discharge, the electrical current may be too low and choose a different one. This tester can provide much needed information on the battery power.

The tester can be used for different types of batteries such as Li-Ion, NiMH, NiCD, or Pb. It utilizes an ATmega168 along with a 16MHz crystal and two 22pF capacitors. The two A/D pins from the Arduino were connected to the added 2.2Ohm resistor that cam e along with an 8Ohm FET. The exact voltage drop on the resistor was obtained by subtracting the values. The software includes auto detecting battery type as the LCD gets connected.