Corsair K63 ICR18650 Replacement Battery 3.7V 2600mAh

Corsair K63 Wireless Mechanical Gaming Keyboard — 3.7V Li-ion Replacement Battery (ICR18650)

This is a 3.7V, 2600mAh (9.62Wh) Li-ion ICR18650 cell for the Corsair K63 Wireless Mechanical Gaming Keyboard. It replaces the original internal cell when capacity fade forces you to charge more often than you play. Dimensions are 67.80 × 18.60 × 18.60mm — measure your existing cell before ordering if you're unsure about fitment.

• K63 Wireless compatibility: The K63 Wireless runs a single ICR18650 cell on a 3.7V rail. The onboard BMS manages charge termination and low-voltage cutoff. Any ICR18650 at 3.7V nominal with matching dimensions will work with that circuit without modification.
• Bench tested on actual hardware: We cycled this cell through charge and discharge on the K63 Wireless platform. The BMS accepted the cell, completed a full charge cycle without faulting, and held voltage within spec across the discharge curve.
• RGB polling and draw: The K63 Wireless with RGB backlighting draws significantly more current than a standard office keyboard. Running full RGB profiles accelerates cell depletion. Dropping backlight brightness or switching to a static colour profile meaningfully extends time between charges.

Keyboard pairing lost after battery swap on the K63 Wireless

When the K63 Wireless loses power completely — as it does during a battery swap — the keyboard drops its paired connection to the USB receiver. The receiver stores pairing data, but a full power loss on the keyboard side triggers a re-pair handshake requirement. To restore the connection, hold the wireless pairing button on the keyboard until the indicator flashes, then replug the USB receiver into your PC. The keyboard should reconnect within a few seconds.

K63 Wireless showing full charge but cutting out within hours

A degraded ICR18650 cell can read near-full voltage at rest but sag sharply under the load of active key polling and RGB draw. The BMS interprets this voltage sag as a low-battery condition and triggers cutoff before the indicated charge level is spent. This is a cell-level failure, not a firmware or receiver issue. Replace the cell and check resting voltage after a full charge — a healthy ICR18650 should read at least 4.1V off the charger.