adidas RPT-01 Wireless Headset Compatible Battery 3.7V 700mAh Li-Polymer

adidas RPT-01 — 3.7V Li-Polymer Replacement Battery (AHB603040)

This 3.7V, 700mAh Li-Polymer cell replaces the original AHB603040 battery in the adidas RPT-01 wireless headset. It restores audio playback and wireless connectivity after the original cell has degraded through repeated charge cycles. Capacity is 2.59Wh, matching the stock specification.

• RPT-01 battery fit: The RPT-01 uses a compact Li-Polymer cell at 42.00 × 29.80 × 6.10mm. That specific footprint and the onboard BMS handshake determine which cells will seat and communicate correctly — the AHB603040 part number confirms the match.
• Bench tested on actual hardware: We cycled this cell through charge and discharge on the RPT-01 platform. The BMS accepted the new pack without error flags, and the protection circuit responded correctly to both low-voltage cutoff and charge termination signals.
• First-cycle charge protocol for the RPT-01: Place the headset in its charging cradle and run a full, uninterrupted charge before first use. The RPT-01's firmware logs the new cell during that first complete cycle — skip it and the talk-time estimate displayed will be inaccurate until the cycle completes.

Why the RPT-01 cuts out mid-audio on a new battery

The RPT-01 pulls simultaneous current for both audio processing and its wireless radio. Under that combined draw, a cell that hasn't completed its first full cycle can sag below the BMS cutoff threshold briefly, dropping the connection. This isn't a faulty cell — it's the protection circuit responding to a momentary voltage dip in an undercharged pack. Running one complete charge cycle before use stabilises the cell voltage and prevents that sag under load.

Talk time shorter than rated on the first few charges

A fresh Li-Polymer cell doesn't deliver full capacity on day one. Internal resistance is slightly higher out of storage, and the electrolyte needs several charge-discharge cycles to fully condition. On the RPT-01, rated talk time typically isn't reached until cycle three to five. Each full charge-discharge pass reduces internal resistance incrementally — by cycle five, measured capacity should be at or close to the rated 700mAh.