Idealens K2 VR Headset Compatible Battery 3.8V 3800mAh

idealens K2 / K2+ — 3.8V Li-Polymer Replacement Battery (904764P)

This is a 3.8V, 3800mAh Li-Polymer battery for the idealens K2 and K2+ standalone VR headsets. Part number 904764P matches the original cell dimensions at 64.50 x 46.50 x 8.80mm and connects directly to the headset's onboard BMS. It restores full charge capacity to headsets where the original cell has degraded through extended use cycles.

• K2 and K2+ platform fit: Both models share the same battery bay, connector pinout, and BMS handshake protocol. The same 3.8V nominal voltage rail powers the display, Qualcomm SoC, and wireless module across both variants, so one cell covers the full K2 line.
• Bench tested on actual hardware: We ran this cell through charge cycles on the K2 platform and confirmed the BMS accepted the cell without fault codes, balanced correctly to 4.35V, and triggered the low-voltage cutoff at the expected floor under combined display and processor load.
• Session voltage stability before VR use: Always charge to 100% before putting on the headset for a long session. The K2's inside-out tracking cameras and motion processors draw heavily at session start — a partially charged cell can sag below the processor's minimum voltage floor within minutes of launching a high-intensity application, triggering drift events that look like sudden tracking jumps.

Why the K2 loses positional tracking when battery drops below 20%

The K2 uses camera-based inside-out tracking, which keeps the vision processors running continuously. At low state of charge, internal resistance in a degraded cell causes voltage to sag under this combined draw. When the supply rail dips below the tracking processor's minimum operating voltage, the headset interprets it as a signal fault and interrupts tracking. A new 3800mAh cell maintains tighter voltage across its discharge curve, reducing the sag that causes this cutoff. If you are already seeing drift events, check battery health in the headset settings — a genuine 3.8V cell should read above 3.6V at rest after a full charge.

Headset shuts down without warning mid-session

An unannounced shutdown on the K2 is almost always a voltage cliff, not a software crash. The combined draw of the display, SoC, wireless radio, and tracking cameras spikes hard during physics-heavy scenes, and a worn cell cannot sustain the current without dropping voltage fast enough to trip the BMS's emergency cutoff. The headset has no time to show a low-battery warning before the BMS disconnects the cell to prevent over-discharge damage. Replace the cell and confirm it charges to 4.35V before the first session — that full-capacity baseline is what prevents the cliff.