Teledex IPN964591 Compatible Battery 3.7V 650mAh

Teledex IPN964591 / IPN965591 Series — 3.7V Li-Polymer Replacement Battery

This is a 3.7V, 650mAh lithium-polymer battery for the Teledex IPN964591, IPN965591, IPN984591, and IPN985591 cordless phone handsets. It slots into the handset battery compartment and restores the handset to full working operation. Dimensions are 42.15 × 31.00 × 6.34mm — confirm your original cell matches before ordering.

• IPN900-series handset compatibility: The IPN964591, IPN965591, IPN984591, and IPN985591 share the same battery bay dimensions, voltage rail, and connector orientation. One cell fits all four models without modification.
• Bench tested on actual hardware: We cycled this cell through charge and discharge on the bench. The protection circuit tripped correctly at the low-voltage cutoff threshold and resumed charging without fault when returned to the base.
• First-charge protocol for Li-Polymer handsets: Li-Polymer cells arrive partially charged from storage. After fitting the new battery, seat the handset in the base and allow a full uninterrupted charge before first use — interrupting the first charge cycle can cause the handset to misread the cell's capacity and report a low-battery warning prematurely.

Talk time shorter than expected after replacing the IPN964591 battery

Li-Polymer cells settle into their rated capacity over the first few charge cycles — the first cycle often delivers noticeably less talk time than the specification. This happens because the cell's internal chemistry hasn't yet reached full electrochemical equilibrium after storage. Run two or three complete charge-and-use cycles and talk time will reach the rated 650mAh output. If it doesn't improve after five cycles, check that the handset contacts are clean and making firm contact with the base cradle.

Handset loses DECT pairing after a battery swap

Removing the battery from a DECT handset cuts all power to the registration memory on some Teledex IPN-series units. When power is restored with the new cell, the handset can no longer authenticate with the base station and shows a "searching" or unregistered status. To fix this, re-register the handset from the base station's handset registration menu — typically accessed by holding the page or find button on the base for five seconds until the registration light flashes. Once re-registered, the handset will reconnect at full signal strength.