Vertical CP2001 IP DECT Compatible Battery 3.7V 1200mAh

Vertical CP2001 IP DECT / RTX CT8010 — 3.7V Li-ion Replacement Battery

This is a 3.7V, 1200mAh Li-ion replacement battery for the Vertical CP2001 IP DECT and RTX CT8010 cordless handsets. It slots into the battery compartment and restores power to the handset unit. No OEM part number is listed for this battery — match by model before ordering.

• CP2001 and CT8010 compatibility: Both handsets share the same battery footprint — 53 x 34 x 5.70mm — and the same 3.7V Li-ion voltage rail. The base station charging circuit targets that voltage, so either handset charges through its cradle contacts without modification.
• Bench tested on actual hardware: We cycled this cell through full charge and discharge passes on the bench. The protection circuit tripped correctly at low-voltage cutoff and allowed clean recharge from the base. No thermal event or false cutoff at ambient temperature.
• First charge after installation: Li-ion cells lose capacity during warehouse storage. After fitting this battery, seat the handset in the base and leave it for a full uninterrupted charge before first use — this brings the cell to rated capacity and lets the protection circuit calibrate to the pack's actual voltage floor.

Talk time shorter than the original battery after replacement

A Li-ion cell shipped from storage arrives partially discharged — sometimes below 3.5V. The handset's fuel gauge, if it has one, may read inaccurate capacity until the cell completes two or three full charge-discharge cycles. The protection circuit also sets its low-voltage threshold on the first few cycles. Run three complete cycles — full charge in base, then use until the handset gives a low-battery alert — before judging capacity against the original. After conditioning, the cell should hold close to its rated 1200mAh.

Handset loses DECT pairing when battery is swapped

Removing the battery cuts all power to the handset, including the memory that stores the DECT pairing token with the base station. When you fit the new battery and power on, the handset may show "searching" or fail to register a call. To fix this, put the base station into registration mode — usually a long press of the page or register button — then trigger pairing from the handset menu. Consult the CP2001 or CT8010 quick-start guide for the exact key sequence, as it differs between firmware versions.