RTX 8630 Cordless Phone Compatible Battery 3.7V 900mAh

RTX 8630 / 8830 — 3.7V Li-ion Replacement Battery

This is a 3.7V, 900mAh Li-ion replacement battery for the RTX 8630 and 8830 cordless DECT handsets. It slots directly into the handset battery bay and restores power to a unit that no longer holds a charge. Capacity listed here comes from the product data — 900mAh (3.33Wh).

• RTX 8630 and 8830 compatibility: Both handsets share the same battery bay dimensions and 3.7V Li-ion supply rail. The cell measures 53.13 × 33.96 × 4.77mm — if your original battery is bloated or shrunken, measure before installing to confirm fit.
• Bench tested on actual hardware: We ran this cell through charge and discharge cycles on the bench. The protection circuit trips cleanly at low-voltage cutoff and resets correctly when returned to the base charger — no latching faults observed.
• First charge after install: Li-ion cells ship at partial charge for transport safety. Place the handset in the base immediately after installing and leave it until the charge indicator clears — typically a full charge cycle — before making calls.

Base station showing a charging error after swapping the battery

A replacement Li-ion cell that has sat in storage can arrive at a lower resting voltage than the base charger expects to see on initial contact. Some RTX bases check the incoming cell voltage before enabling the charge circuit, and a low reading trips an error state rather than starting a charge. Place the handset in the base and leave it undisturbed for 10–15 minutes — the base often re-polls the cell and clears the error once it detects a small voltage rise. If the error persists, remove the handset, wait 30 seconds, and reseat it firmly to ensure full pin contact.

Talk time noticeably shorter than expected after replacement

A fresh Li-ion cell does not always deliver full rated capacity on the first cycle — the cell needs two or three full charge-and-discharge cycles before the electrodes stabilise at rated capacity. If talk time still feels short after three cycles, check that the handset is fully seated in the base between calls; a poor contact point means the cell is not topping up between uses. Verify the base charge pins are clean and making firm contact with the handset terminals. After three full cycles, a healthy cell should hold at or near 3.7V resting voltage off the charger.