A battery tester engages a power tool battery and includes a housing having a cavity for receiving a stem of the power tool battery. The battery tester has a plurality of electrically conductive contacts disposed in the cavity and is configured to engage corresponding battery electrodes on the stem. A processor is mounted within the housing and communicates with the battery through the electrically conductive contacts. The processor measures a voltage level of the battery, and a loading circuit electrically loads the battery during measuring. One or more indicators are controlled by the processor. The processor activates the loading circuit for a predetermined period of time to measure a voltage level of the battery while under load, and then activates the indicators to provide a visual indication of remaining battery life. The battery tester is a stand-alone device where housing does not have a motor or a battery charger.