Corsair H2100 Replacement Battery 3.7V 700mAh MH45908

Corsair H2100 Series — 3.7V Li-Polymer Replacement Battery (MH45908)

This is a 3.7V, 700mAh Li-Polymer replacement battery for the Corsair H2100 and Gaming H2100 Dolby 7.1 Wireless Gaming Headset. It fits models CA-9011136-AP and CA-9011127-NA, among others. When the original cell can no longer hold a charge, this swap restores wireless audio and DECT radio function.

• H2100 series compatibility: All listed H2100 variants share the same 3.7V Li-Polymer cell, connector pinout, and BMS handshake requirement through the base station dock. Swapping within this family does not require firmware changes.
• Bench tested on actual hardware: We cycled this cell through the H2100 base station and confirmed the BMS completed its handshake, accepted a full charge cycle, and delivered stable voltage under simultaneous audio and DECT radio draw.
• First-charge protocol for the H2100: Seat the headset in the base station and let it complete one uninterrupted full charge before use. The base logs the new cell during this cycle — skip it and the talk-time indicator will read inaccurately for several sessions.

Base station not recognising the new pack after swap

The H2100 base station uses a BMS handshake to register a new cell before it will display charge status or enable wireless pairing. If the base shows no charging activity after a battery swap, the cell likely arrived at storage voltage — around 3.6V — which can prevent the handshake from initiating. Place the headset firmly in the cradle and leave it connected for at least 15 minutes without moving it. Once the base acknowledges the cell, the charge indicator will activate and the full cycle can complete normally.

Headset cuts out mid-call even with a freshly charged battery

The H2100 draws current simultaneously from two loads: the audio driver and the DECT radio transmitter. Under that combined draw, a cell with even minor capacity fade can sag below the BMS cutoff threshold before the charge indicator suggests it should. This is a voltage-sag failure, not a capacity failure — the cell reads as charged but cannot sustain the peak current spike. If cut-outs happen consistently during calls but not during standby audio, check that the cell voltage under load does not drop below 3.2V, which is the typical BMS trip point for this cell class.