DeTeWe DT413 Replacement Battery 3.7V 1100mAh Li-ion

DeTeWe DT413 / DT423 — 3.7V Li-ion Replacement Battery

This is a 3.7V 1100mAh (4.07Wh) lithium-ion battery for the DeTeWe DT413 and DT423 cordless DECT handsets. It replaces the original cell when the handset no longer holds a charge or stops powering on. Dimensions are 73.60 × 43.50 × 11.00mm — verify these against your existing pack before ordering.

• DT413 and DT423 compatibility: Both handsets share the same battery bay dimensions, connector pinout, and 3.7V supply rail. One cell fits both models without modification.
• Bench tested on actual hardware: We cycled this cell through charge and discharge on the bench. The BMS held cutoff correctly at both ends — no overcharge trip, no premature low-voltage shutdown under simulated standby and active RF load.
• First charge after installation: Place the handset in the base station immediately after fitting this battery and leave it for a full 16 hours before use. Li-ion cells shipped in storage state need a slow, complete first charge to calibrate the BMS fuel gauge and reach rated capacity.

Why the DT413 shows reduced range after a battery swap

The DT413's DECT radio module draws a short current spike every time it transmits a burst. If the replacement cell has a higher internal resistance than the original — common with cells that have sat in storage — the voltage sags under that RF load. The handset's transmit power drops when supply voltage falls below threshold, which shortens the usable range noticeably. After 3 to 5 full charge cycles, internal resistance drops and the voltage sag stabilises. Range typically recovers on its own without any configuration change.

Handset not pairing with the base after battery replacement

Removing the battery cuts all power to the DT413's RAM, which can erase the stored DECT pairing data. When the handset restarts with a new cell, the base station may not recognise it and will refuse to register calls. To fix this, put both base and handset into manual pairing mode — on most DeTeWe systems this means holding the registration button on the base for 3 seconds until the LED flashes, then triggering the pairing sequence from the handset menu. The handset will re-register as a new device and resume normal operation.