Corsair K57 RGB Wireless Gaming Keyboard Replacement Battery RDJ15 3.7V 2600mAh Li-ion

Corsair K57 RGB Wireless Gaming Keyboard — 3.7V Li-ion Replacement Battery (RDJ15)

This 3.7V 2600mAh Li-ion battery replaces the internal RDJ15 cell in the Corsair K57 and K57 RGB Wireless Gaming Keyboard. It restores power to both the wireless receiver link and the onboard RGB lighting. Fit the correct cell and the keyboard returns to full function — no firmware changes needed.

• K57 and K57 RGB compatibility: Both variants share the same internal battery bay, connector pinout, and BMS handshake. The RDJ15 part number covers the full K57 wireless line, so one cell fits every board in that range.
• Bench tested on actual hardware: We cycled this cell through charge and discharge on a K57 RGB unit. The onboard BMS accepted the cell without flagging a fault, RGB lighting initialised at full brightness, and the 2.4GHz wireless link held stable throughout testing.
• RGB draw and charge cycles: The K57 RGB runs lighting and wireless simultaneously from this single cell. Heavy RGB profiles accelerate cycle count faster than office keyboards. Keep RGB effects at mid-brightness when the keyboard is on battery to extend cell life between charges.

Pairing lost after replacing the K57 battery

A full power loss wipes the volatile pairing state on some Corsair wireless keyboards. When the K57 loses all cell voltage during a swap, the USB receiver can no longer find the keyboard on first boot. Unplug the USB receiver, hold the keyboard's wireless connect button for three seconds, then re-insert the receiver. The keyboard re-advertises and the receiver locks on within a few seconds.

K57 RGB shows charging but voltage won't climb past 3.5V

A cell that sits discharged for an extended period can drop below the BMS recovery threshold, typically around 2.5V. At that point the charger circuit enters trickle mode and may stall before reaching the 4.2V full-charge target. If the keyboard charges for over two hours and the indicator still shows partial, remove the cell, wait 60 seconds, refit it, then reconnect USB power. This resets the charge controller handshake and allows a normal CC/CV charge cycle to begin.