About this replacement
Streamlight Strion HPL / Strion LED Series — 3.7V Li-ion Replacement Battery (74031)
This 3.7V 2600mAh (9.62Wh) Li-ion battery replaces the original cell in the Streamlight Strion HPL, Strion LED, Strion DS HL, and ProTac HL USB flashlights. It fits the full Strion platform — over 30 OEM part numbers share this cell format, including 74031, 74032, 74175, and 74331. Voltage and capacity match OEM spec exactly.
- Strion platform compatibility: Every Strion-series light in this family runs the same 3.7V single-cell architecture with a common connector and BMS handshake. That shared voltage rail is why one battery covers the HPL, DS HL, ProTac HL USB, and the broader Strion LED lineup without modification.
- Bench tested on actual hardware: We cycled this cell through full charge and discharge on a Strion HPL body. The BMS tripped correctly at low-voltage cutoff, and the charge circuit accepted the cell without fault codes or thermal events across multiple cycles.
- Strion charge port care: The Strion's built-in USB or cradle charging circuit monitors cell temperature during charge. If the flashlight body is hot from extended use, wait until it cools before seating it in the charger — charging a warm cell in a hot body can trigger a premature charge termination that leaves the cell only partially full.
Strion HPL output stepping down before the indicator shows low
The Strion HPL driver watches cell voltage in real time and steps output down when voltage sags — even if the fuel gauge still reads partial charge. At high output, the cell is under heavy current draw, so voltage drops faster than the indicator can reflect. This is driver brownout protection, not a faulty battery. If the light dims mid-use, switch to a lower mode to bring voltage back above the driver's threshold and restore stable output.
Significantly shorter run in turbo mode versus high or medium
Turbo mode on the Strion HPL draws several times more current than high or medium modes. That higher draw pulls cell voltage down faster and trips the driver's low-voltage step-down much earlier in the discharge cycle. The battery isn't faulty — the same cell capacity lasts far longer at lower output levels where current draw stays inside the cell's sustained discharge rating. If turbo endurance is critical, switch to high mode and reserve turbo for short bursts only.