Unlike the most common testers, the XT1 can reliably test nearly all types of batteries and accumulators. It measures battery voltage in volts, percentage capacity, and internal resistance, which is typically reserved for very expensive measuring devices in the industrial sector. The device features a current mode and offers an energy-saving mode. It comes with two contact pins and is intended for use in protected indoor areas away from sunlight. It requires 2x AAA batteries (do not use rechargeable batteries, only 1.5 V alkaline batteries), which are not included.