Triplett BR500 Borescope Replacement Battery 3.7V 2600mAh

Triplett BR500 / BR750 Articulating Borescope — 3.7V Li-ion Replacement Battery (ICR18650)

This 3.7V, 2600mAh (9.62Wh) Li-ion ICR18650 cell replaces the factory battery in the Triplett BR500 High Definition Articulating Borescope and BR750 High Definition Articulating Videoscope. Both units use a single 18650 format cell to power the camera module, articulation control, and LED illumination array. Capacity is sourced from the product data — 2600mAh at 3.7V nominal.

• BR500 and BR750 platform fit: Both models share the same 18650 cell bay, 3.7V nominal rail, and BMS communication handshake. The articulation motor and camera sensor draw from the same cell, so the cell must meet minimum discharge rate thresholds to avoid mid-session cutoff under combined load.
• Bench tested on actual hardware: We ran this cell through power-on sequencing, LED activation, and articulation motor cycling. The BMS held cell voltage above the cutoff threshold during motor-start current spikes and maintained stable output to the camera module under sustained load.
• First-use initialisation on the BR500/BR750: After fitting the new cell, navigate to the BR500/BR750 display menu and run a full power cycle — power on, allow the camera and LED system to fully initialise, then power off cleanly via the menu. This allows the instrument's charge state logic to map the new cell's baseline voltage and prevents false low-battery warnings during your first inspection session.

BMS cutoff when the LED array or articulation motor fires up

The BR500 and BR750 draw peak current in two moments: LED array activation at power-on, and articulation motor engagement when you steer the probe head. An aged or deeply discharged cell may sit at a resting voltage that looks acceptable, but internal resistance causes a sharp voltage sag the instant either load fires. The BMS reads that sag as an undervoltage fault and shuts the unit down. A new cell with lower internal resistance handles the transient current spike without triggering the cutoff — the sag stays within the BMS acceptance window, typically above 2.8V under load.

BR500 display showing a full charge bar that drops immediately after unplugging from charge

This is the instrument's voltage-threshold indicator recalibrating to the new cell's charge profile. The original firmware maps percentage thresholds against the aged cell's discharge curve, so a fresh cell at 4.15V can briefly read higher than expected, then step down quickly once the unit draws current and the indicator recalibrates. Run two full charge and discharge cycles through normal inspection use — do not interrupt them — and the display percentage will stabilise against the new cell's actual capacity curve. After the second cycle, the bar should track accurately through the full discharge range.