Pentax D-LI63 Optio L36 Replacement Battery 3.7V 660mAh

Pentax Optio L36 / L40 / LS1000 — 3.7V Li-ion Replacement Battery (D-LI63 / D-LI108)

This is a 3.7V 660mAh Li-ion cell that replaces the D-LI63 and D-LI108 batteries used in the Pentax Optio L36, L40, LS1000, LS1100, and over a dozen additional Optio compact cameras. It fits the same slim 40.00 × 31.10 × 5.90mm footprint as the original. Use it when the OEM cell no longer holds a charge or reads incorrectly on the camera's battery indicator.

• Optio L-series and LS-series compatibility: These Pentax compact models share the same battery bay geometry, contact pin layout, and voltage rail. The D-LI63 and D-LI108 part numbers refer to functionally identical cells — same chemistry, same dimensions — issued across different production runs of the Optio line.
• Bench tested on actual hardware: We ran this cell through charge and discharge cycles with the Optio L36 body. The BMS handshake completed on the first charge via the OEM charger, and the battery-remaining indicator updated normally through the full discharge curve.
• First-install charge cycle: Insert the cell and run one full charge inside the OEM charger or camera body before your first shoot. Some Optio bodies require an internal charge cycle to calibrate the battery-remaining display — skipping this step can cause the indicator to read full and then drop suddenly.

Why the Optio L36 shows a dead battery icon on a partially charged replacement cell

The Optio L36 maps its battery indicator to a voltage-threshold table built around the OEM cell's discharge curve. A new third-party cell may sit at 3.85V resting voltage and still trigger the low-battery icon because the camera has never seen that cell's charge state before. This is not a fault with the replacement — it is the camera's indicator reading from an uncalibrated baseline. Charge the cell fully via the OEM charger, then power on the camera. After one complete charge-to-discharge cycle the indicator typically tracks correctly.

Battery percentage jumping erratically on the Optio display after fitting a new cell

This happens when the camera's stored discharge map no longer matches the new cell's voltage profile mid-cycle. The Optio reads voltage at set intervals and converts that to a percentage — if the new cell drops voltage more steeply in the mid-range than the original did, the display jumps. It does not mean the cell is faulty. Run two full charge cycles from 0% to 100% and the camera's internal voltage-to-percentage mapping will stabilise. If the display still jumps after two cycles, verify resting voltage with a multimeter — a healthy cell at full charge reads between 4.15V and 4.20V.