About this replacement
Hollyland Solidcom M1 — 3.8V Li-Polymer Replacement Battery (HL-BAT1500)
This 3.8V, 1500mAh Li-Polymer cell replaces the HL-BAT1500 battery in the Hollyland Solidcom M1 wireless intercom headset. The Solidcom M1 is used on film sets, live broadcasts, and stage productions where communication cannot drop. Swap a depleted cell and keep the headset running through back-to-back sessions.
- Solidcom M1 fit: The M1 headset runs a single-cell 3.8V Li-Polymer pack with a dedicated BMS that handshakes with the base station during charging. This replacement matches the voltage rail, physical footprint (46.50 × 33.00 × 9.00mm), and connector orientation the base station expects.
- Bench tested on actual hardware: We cycled this cell through the Solidcom M1 base station and confirmed the BMS completed a full charge handshake without error flags. Current draw under simultaneous audio output and DECT radio transmission stayed within the cell's continuous discharge rating.
- First charge in the base station: Place the headset in the Solidcom M1 base station and run a complete charge cycle before taking a call. The base station logs the new cell during this cycle — until it does, the talk-time indicator will not read accurately.
Base station not recognising the new pack after swap
The Solidcom M1 base station uses a BMS handshake to identify and register a battery before it will display charge status. If the cell arrives at storage voltage (typically around 3.6–3.7V), the base may show no charge activity or a blinking error light on first insertion. Remove the headset, reseat it firmly, and leave it undisturbed for a full charge cycle. Once the BMS completes initialisation, the status LED will switch to solid and charging will proceed normally.
Headset cuts out mid-transmission on a new battery
The M1 pulls combined current for both the audio circuit and the DECT radio simultaneously — this is a higher instantaneous draw than standby suggests. A cell in its first few cycles has not yet reached full electrochemical capacity, so voltage can sag under that combined load and trip the BMS undervoltage cutoff. This is not a fault with the battery. Run three to five full charge-discharge cycles through normal use and the cutout threshold will stop being triggered as usable capacity builds up.