The TriMetric battery monitors are designed to assist in battery care, conservation and system maintenance of battery powered systems that use storage batteries with system voltage from 12-48 volts. They provide the user with information on battery "volts", "amps" and "amp-hours" and the newest version also provides "battery percent full" information, based on measuring the amp-hours removed from the battery system. Reliability, accuracy and simplicity are key product objectives. The TriMetric requires an external shunt located near the batteries to measure "amps" and "amp-hours". The meter readout may be located hundreds of feet away from batteries and is usually connected to the shunt with a 4 wire cable. The newest version of TriMetric (Model TM-2020) has been available since April 1998 and incorporates some "user friendly" improvements including a "Battery % full" display, and a "battery reminders" feature to help users to better care for batteries which should make it the more favored choice for most users. However all TriMetrics measure "volts" "amps" and "amp-hours" with the same accuracy. Image shown with optional white double gang box.