BTL20 is an intelligent test probe designed for the Fluke 500 Series Battery Analyzers, featuring an integrated LCD display for real-time measurement feedback. The probe measures internal battery resistance, DC and AC voltage, DC and AC current, ripple voltage, frequency, and temperature, with measurement ranges including 3 mO to 3000 mO for resistance, 6 V to 1000 V for DC voltage, and 600 V for AC voltage. It supports automatic or manual sequence testing of battery strings with automatic measurement storage, eliminating the need to manually save each reading. The probe includes rugged coaxial two-pole Kelvin test pins with a remote SAVE button, and is compatible with test probe extenders for long reach and angled access to double-stacked cells. BTL20 is ideal for maintenance, troubleshooting, and performance testing of stationary batteries, providing reduced testing complexity and simplified workflow through an intuitive user interface.