Hollyland HL-BAT700 Solidcom C1 Replacement Battery 3.8V 800mAh

Hollyland Solidcom C1 / C1 Pro — 3.8V Li-ion Replacement Battery (HL-BAT700)

The HL-BAT700 is a 3.8V, 800mAh Li-ion cell for the Hollyland Solidcom C1 and Solidcom C1 Pro wireless intercom headsets. It slots directly into the headset body and powers both the audio circuit and the DECT radio simultaneously. Replace this cell when the original shows capacity fade after repeated charge cycles.

• Solidcom C1 and C1 Pro compatibility: Both models use the same HL-BAT700 cell, the same connector pinout, and the same BMS handshake protocol with the base station. Swapping between models is not a concern — the base reads the new pack the same way on either headset.
• Bench tested on actual hardware: We cycled this cell through charge and discharge on the Solidcom C1 base station. The BMS completed its handshake on the first dock, and the charge indicator stepped through its stages normally with no error flags thrown.
• First dock after fitting: Seat the headset in the base station and let it complete one full charge cycle before making any calls. DECT headsets log the new cell during that first cycle — until it finishes, the base station's talk-time estimate will read short or not at all.

Why the Solidcom C1 cuts out mid-call even with a charged battery

The Solidcom C1 draws from two loads at once: the audio processing circuit and the DECT radio transmitter. When both fire simultaneously — especially during a loud burst of audio — the combined current pull can spike briefly beyond what a degraded or cold cell can deliver. The BMS interprets that voltage sag as an undervoltage condition and cuts the output to protect the cell. A new HL-BAT700 at full charge handles the combined draw without sagging into the BMS cutoff threshold, which sits below 3.0V under load.

Base station shows full charge but headset shuts off after a few minutes

This usually means the cell arrived at storage voltage — around 3.7V — and the base station misread that as a near-full charge, topping it off only slightly before showing the full indicator. The headset then exhausts the actual shallow charge within minutes. The fix is straightforward: drain the headset through normal use until it powers off, then dock it and let the base run a complete charge cycle from low. After that first full cycle, the base station's charge estimate will track accurately.