Logitech G733 Replacement Battery 3.7V 1500mAh Li-Polymer

Logitech G733 — 3.7V Li-Polymer Replacement Battery (533-000181)

This 3.7V, 1500mAh Li-Polymer cell replaces the original 533-000181 battery in the Logitech G733 wireless gaming headset. It restores wireless audio and LIGHTSPEED connectivity when the original cell no longer holds a usable charge. Dimensions are 51.00 x 39.60 x 6.00mm — confirm fit before installing.

• G733 platform fit: The G733 uses a fixed 3.7V Li-Polymer pack matched to its onboard BMS and LIGHTSPEED radio circuit. Voltage and connector position must match exactly — the BMS monitors cell state continuously and will not power the headset if either is off.
• Bench tested on actual hardware: We ran this cell through charge and discharge cycles on the G733 platform. The BMS accepted the pack cleanly, charge termination triggered correctly at full voltage, and the LIGHTSPEED receiver maintained a stable link throughout.
• First charge after installation: Place the G733 in its charging cradle and run a complete charge cycle before use. The headset's firmware uses that first full cycle to calibrate the battery state indicator — skipping it causes the charge display to read inaccurately from the start.

Why the G733 cuts out mid-session on a new battery

The G733 draws from both the audio amplifier and the LIGHTSPEED 2.4GHz radio simultaneously. Under that combined load, a cell at partial or storage voltage can sag below the BMS cutoff threshold even if the indicator shows charge remaining. This is not a defective cell — it is the BMS protecting the pack from under-voltage. Running one full charge cycle before the first session brings the cell to operating voltage and prevents the sag-triggered cutoff.

Talk time shorter than rated across the first few sessions

Li-Polymer cells ship at storage voltage, not full capacity. On the first two to three cycles, usable capacity sits noticeably below the rated 1500mAh. This is normal cell behaviour — capacity builds toward rated spec across three to five full charge and discharge cycles. If talk time is still short after five cycles, check that the charging cradle contacts are clean and making solid contact with the headset's charge pins.