Uniden DCX770 Replacement Battery BT-0001 3.7V 750mAh

Uniden DCX770 / DMX776 Series — 3.7V Li-ion Replacement Battery (BT-0001)

This 3.7V 750mAh Li-ion battery replaces OEM part BT-0001 (also listed as BBTY0531001) in Uniden cordless handsets. It fits the DCX770, DMX776, DMX778, and WDECT 2385 series. These models share the same cell format, connector pinout, and voltage requirement, so one battery covers the full range.

• DCX770 / DMX776 / WDECT 2385 platform fit: These handsets run off the same 3.7V single-cell Li-ion architecture. The connector, BMS communication line, and physical dimensions — 50.32 × 30.77 × 4.74mm — are identical across the range, so the same pack drops straight in without any modification.
• Bench tested on actual hardware: We cycled this pack through charge and discharge on a DCX770 handset. The BMS accepted charge current from the base station without triggering a fault, held voltage within spec at load, and passed protection cutoff checks at both ends of the discharge curve.
• First charge after installation: Place the handset in the base immediately after installing this battery and leave it for a full 16 hours before first use. Li-ion cells shipped from storage sit at a partial state of charge — a full conditioning charge ensures the BMS calibrates its capacity tracking correctly from cycle one.

Talk time shorter than the original battery after replacement

A new Li-ion cell shipped from storage will often deliver noticeably less talk time for the first few charge cycles. This is not a fault — the BMS has not yet mapped the cell's full capacity range and will cut off discharge earlier than necessary. Run three to five full charge and discharge cycles through normal handset use. By cycle five, capacity tracking stabilises and talk time reaches the rated level.

Handset loses pairing with the base after battery swap

Removing the battery from a DECT handset cuts power completely, and some Uniden models lose their stored pairing data when the cell drops out. The handset will show no line or fail to register on the base after reinstall. To fix this, hold the handset's Find/Page button while it is seated in the base, or run a fresh DECT registration from the base station menu — refer to the model's pairing sequence, which typically completes in under 60 seconds.