Baofeng BP-011 2-Way Radio Replacement Battery 3.7V 900mAh

Baofeng BF-666S / BF-888S Series — 3.7V Li-ion Replacement Battery (BP-011)

This is a 3.7V 900mAh Li-ion battery for the Baofeng BF-666S, BF-777S, BF-888S, and BF-666-S handheld two-way radios. It replaces OEM part numbers BP-011 and BL-1. The pack slots into the standard Baofeng battery bay on all listed models using the same connector and contact layout as the original.

• BF-666S / BF-777S / BF-888S platform fit: These three radios share the same 3.7V single-cell Li-ion architecture, battery bay dimensions, and contact strip arrangement. One pack covers all of them — no adapters needed.
• Bench tested on actual hardware: We cycled this pack through full charge and PTT-keyed transmit loads on the BF-888S. The BMS held cutoff at the correct low-voltage threshold and did not trip during sustained TX bursts.
• First insertion contact check: If the charger shows a fault LED on first insertion, remove the pack, wipe the gold contact strip with a dry cloth, and reseat firmly. The Baofeng dock needs a clean contact cycle to handshake with the new BMS before charging begins.

Why the BF-666S cuts out mid-transmission on a freshly inserted battery

New cells ship at storage voltage — typically around 3.6V — not at full charge. On the BF-666S, the transmit current spike when you press PTT can pull the cell voltage down briefly, triggering the BMS undervoltage cutoff before the radio finishes the transmission. This is not a faulty pack. Charge the battery fully before first use and the cutoff will not trigger mid-keying under normal TX loads.

Bar indicator showing one fewer bar than expected after a full charge cycle

The BF-888S and BF-666S use a simple voltage-threshold bar indicator — not a capacity-counting chip. If the radio sat on the charger but the dock light cycled off before the cell reached 4.2V, the indicator reads one bar low. Remove the pack, reinsert it, and return it to the dock. Verify the dock light goes solid green and holds there — that confirms the cell reached the 4.2V full-charge threshold.