iDect X2 Cordless Phone Compatible Battery 3.7V 500mAh

iDect X2 Series — 3.7V Li-Polymer Replacement Battery (MT LP053040)

This is a 3.7V, 500mAh lithium-polymer cell replacing the MT LP053040 in iDect X2 series cordless handsets. It fits the X2, X2d, X2i, and X2di. The cell restores power to the handset so it can register with the base station and carry calls normally.

• X2 series handset compatibility: The X2, X2d, X2i, and X2di all run the same 3.7V Li-Polymer cell at this footprint — 41.90 × 29.24 × 5.07mm. The connector pinout and BMS handshake are identical across the range, so one cell covers all four variants.
• Bench tested on actual hardware: We cycled this cell through charge and discharge on a DECT handset rig. The BMS held the charge rail stable throughout standby draw and peaked cleanly during the RF transmit bursts the DECT protocol fires every 10ms.
• First charge on the iDect base station: Seat the handset in the base immediately after fitting the new cell. Leave it there undisturbed for a full 16 hours before the first call. The iDect base charges at a low trickle current — pulling the handset out early cuts the initialisation cycle short and reduces usable capacity from the first use.

Talk time shorter than expected after fitting this cell

Li-Polymer cells in DECT handsets sometimes deliver below rated capacity for the first two or three full cycles. The BMS calibrates its charge endpoint against actual cell behaviour — not factory defaults. Run three full charge-and-discharge cycles through the iDect base before judging capacity. By cycle three, the BMS will have mapped the cell correctly and talk time will stabilise at the rated level.

Handset fails to re-pair with the base after battery replacement

Removing the old cell cuts all power to the handset, which clears the DECT registration stored in RAM on some iDect models. The handset comes back up with no base link and sits idle. On the X2 series, press and hold the Paging button on the base for three seconds, then use the handset menu to run a fresh registration. The base will confirm pairing with a short tone once the handset is accepted.