Oregon CT-3650 Compatible Battery 3.7V 1050mAh Li-ion

Oregon CT-3650 — 3.7V Li-ion Replacement Battery

This is a 3.7V, 1050mAh lithium-ion replacement cell for the Oregon CT-3650 digital camera. It slots into the same battery compartment as the original and supplies the voltage rail the camera body expects. Capacity matches the OEM spec at 3.89Wh.

• CT-3650 platform fit: The CT-3650 draws from a single-cell 3.7V Li-ion architecture. The connector orientation and cell dimensions — 52.92 × 33.78 × 5.48mm — match the original bay. The BMS in the camera monitors voltage thresholds that this cell satisfies at charge, discharge, and standby.
• Bench tested on actual hardware: We cycled this cell through charge and discharge on camera-class equipment. The BMS accepted the cell without tripping low-voltage cutoff at start-up, and the protection circuit responded correctly at both ends of the charge window.
• First-install charge cycle: On first use, run a full charge inside the camera body or OEM charger before shooting. Some CT-3650 firmware maps the battery-remaining indicator against a charge baseline recorded on that first cycle — skipping it can cause the display to read erratically from the first frame.

Camera battery indicator stuck at full or dropping suddenly mid-shoot

The CT-3650 estimates remaining charge by comparing real-time cell voltage against a stored discharge curve. A new cell with a slightly different internal resistance profile can cause the indicator to lag, jump, or flatline until the camera recalibrates. This recalibration happens across one or two full discharge-to-recharge cycles. After those cycles, the displayed percentage tracks the actual state of charge accurately.

Camera shows "no battery" or refuses to power on with new cell installed

This is a BMS handshake issue, not a dead cell. The camera checks for a minimum open-circuit voltage on insertion — if the replacement cell shipped at a low storage charge, it may fall below that threshold. Remove the cell, charge it fully in an external charger or via the camera's USB port, then reinsert. The camera should recognise the cell once resting voltage reads above 3.6V.