Cobra 2130099001 Replacement Battery 3.6V 1200mAh Ni-MH

Cobra 2130099001 / CP100 Series — 3.6V Ni-MH Replacement Battery

This 3.6V 1200mAh Ni-MH battery replaces the original pack in Cobra cordless phones including the 2130099001, CP100, CP100S, CP100SA, and over 20 additional handset models. It restores handset operation away from the base station when the original cell has degraded or failed to hold a charge. Voltage, capacity, and connector orientation match the factory specification.

• CP100 Series compatibility: These handsets share a common 3.6V single-cell NiMH bay with identical connector pinout and BMS charge-acceptance logic, so one pack covers the full CP100 family without modification.
• Bench tested on actual hardware: We cycled this pack through the Cobra base charging circuit and confirmed the BMS accepted charge from the first dock. Voltage climbed steadily from resting state with no error light triggered.
• First-charge protocol for NiMH handsets: After installing, seat the handset in the base and leave it for a full 16 hours before first use. NiMH cells in cordless phones are shipped partially discharged — skipping this slow initial charge leaves usable capacity on the table for the first several cycles.

Base station showing no charge or error light after fitting a new pack

Cobra base stations use a voltage threshold to confirm a battery is present before starting the charge cycle. A NiMH pack that has sat in storage can drop below that threshold — typically under 3.0V — and the base reads it as a fault rather than a dischargeable cell. The fix is a brief trickle charge: some bases will re-attempt after a 30-minute rest in the cradle, others need the handset removed and re-seated. If the error clears and voltage climbs past 3.2V, the base will take over and complete the charge normally.

Talk time shorter than the original battery for the first few uses

NiMH cells do not deliver rated capacity on the first cycle — this is normal chemistry behaviour, not a fault. Cobra handsets using this pack typically reach close to rated 1200mAh capacity after three to five full charge-discharge cycles. Do not judge the pack on day one. Run the handset until it drops, return it to the base for a full 16-hour charge, and repeat. By cycle five, capacity should stabilise near the rated figure.