Coast FL60R Replacement Battery 3.7V 1300mAh Li-Polymer

Coast FL60R / FL75R / FL85R — 3.7V Li-Polymer Replacement Battery

This 3.7V, 1300mAh lithium-polymer battery replaces the internal rechargeable cell in the Coast FL60R, FL75R, and FL85R flashlights. All three models share the same cell format and connector, so one part number covers the range. Dimensions are 44.70 × 35.00 × 12.20mm — confirm your existing cell matches before ordering.

• FL60R, FL75R, FL85R compatibility: These three flashlights use the same cell footprint and the same driver board voltage rail. The shared form factor means the BMS handshake and connector orientation are identical across all three models.
• Bench tested on actual hardware: We cycled this cell through full charge and discharge on the FL60R driver board. The BMS held charge termination at the correct cutoff voltage and stepped down output at the low-voltage threshold without tripping into a protection lockout.
• Turbo mode thermal behaviour: The FL-series driver runs turbo at significantly higher current draw than standard or mid modes. Extended turbo use heats the cell faster than standard cycling does — switch to mid mode if the body gets warm to the touch, which keeps the cell within its safe operating temperature range.

FL60R driver stepping down output before the indicator shows low

The FL-series driver uses a brownout protection threshold that sits above the battery's actual empty voltage. When cell voltage drops under high-current draw, the driver cuts output to a lower mode before the indicator registers low battery. This is intentional — the driver protects the cell from voltage collapse under load. You'll notice this most in turbo mode, where current draw is highest. If the light steps down unexpectedly, check cell voltage at rest; anything below 3.5V means the cell needs charging.

Flashlight not powering on after long storage

Lithium-polymer cells that sit discharged for months can drop below the BMS re-initialisation threshold, typically under 2.5V. At that point the protection circuit opens and the driver sees no voltage — the light appears completely dead. Place the cell on a compatible charger that supports recovery or trickle-charge mode. If cell voltage recovers to at least 3.0V within 15 minutes of trickle input, the BMS will re-engage and normal charging can resume.