Sony MDR-DS7000 Replacement Battery BP-HP1200 3.7V 1200mAh

Sony MDR-DS7000 / MDR-RF7100 Series — 3.7V Li-Polymer Replacement Battery (BP-HP1200)

This is a 3.7V, 1200mAh lithium-polymer replacement for the Sony BP-HP1200 battery cell. It fits the MDR-DS7000, MDR-RF7000, and MDR-RF7100 wireless headset systems. Swap this in when the original cell no longer holds enough charge to get through a full listening session.

• MDR-DS7000, RF7000, RF7100 compatibility: All three models share the same battery bay geometry, connector pinout, and 3.7V nominal rail. The BMS handshake protocol is identical across this headset family, so the base station charges and communicates with this cell the same way it did with the original.
• Bench tested on actual hardware: We ran this pack through charge and discharge cycles on the MDR-RF7100 base station. The BMS completed the handshake correctly, the charge indicator stepped through its stages without error, and the headset powered on and maintained audio output without voltage-sag dropout.
• First charge after fitting: Place the headset in the base station immediately after fitting this cell and let it complete one full uninterrupted charge cycle before use. DECT-based headsets log the new cell's state-of-charge baseline during that first cycle — skipping it causes the talk-time indicator to read inaccurately for the first week of use.

Base station showing full charge but headset cuts off after short use

A replacement cell ships at storage voltage — typically 3.6V to 3.65V, not a full 3.7V charge. The base station's charge circuit may reach its termination threshold quickly and display a full-charge indicator before the cell has actually received a complete cycle. The headset then runs down faster than expected because it started at a partial state of charge. One full uninterrupted charge from the base station resolves this on the first cycle.

Headset cuts out mid-programme but base shows no error

The MDR-DS7000 and RF7100 combine audio decoding and a DECT radio transmitter in the same housing, drawing current from a single small cell. When the cell voltage dips under that combined load — particularly during loud audio passages that spike DSP draw — the BMS interprets the sag as a low-cell event and cuts output before the battery is fully depleted. This is not a fault with the battery; it is the BMS protecting the cell. If dropout happens repeatedly at normal volume, confirm the cell has completed at least three full charge-discharge cycles, which typically brings resting voltage up to a stable 3.7V.