RCB215 Doro Primo 215 Compatible Battery 3.7V 1200mAh

Doro Primo 215 / PhoneEasy 332 Series — 3.7V Li-ion Replacement Battery (RCB215)

This is a 3.7V, 1200mAh Li-ion cell replacing the original RCB215 battery in the Doro Primo 215 and PhoneEasy 332 series — senior-friendly mobile phones built around straightforward calling and texting. The same cell covers the Primo 405 under OEM part number RCB405. Physical dimensions are 53.00 × 33.90 × 5.70mm — confirm against your existing cell before installing.

• Primo 215, PhoneEasy 332, PhoneEasy 332GSM, Primo 405: These models share the same battery bay dimensions and a single-cell 3.7V architecture with identical connector pinout. One cell covers the full group because the BMS handshake logic is identical across this platform.
• Bench tested on actual hardware: We cycled this cell through charge and discharge on a Primo 215 unit. The BMS accepted the cell without fault flags, charge termination triggered correctly at full voltage, and the protection circuit tripped cleanly at the low-voltage cutoff threshold.
• Fuel gauge recalibration on first use: After fitting this cell, run one complete discharge down to auto-shutdown, then charge uninterrupted to 100%. The phone's fuel gauge IC was calibrated to the old cell's discharge curve — skipping this step causes the percentage display to read inaccurately for the first several cycles.

Why the Primo 215 shuts off suddenly at 20–30% after a battery swap

This happens because the fuel gauge IC still holds the discharge curve of the old, degraded cell in memory. The new cell has a steeper voltage cliff under load than the IC expects, so the phone reads 25% on screen while the actual cell voltage has already dropped below the modem's minimum operating threshold. The modem draws a surge during a call attempt, the voltage collapses faster than the gauge can track, and the protection circuit cuts power. One full discharge-to-shutdown followed by a complete uninterrupted charge resets the coulomb counter and resolves this.

Phone shows wrong battery percentage after fitting the new cell

The fuel gauge IC in these Doro phones stores a learned charge curve from the previous cell. A fresh cell with different internal impedance throws off those stored values immediately. You will see the percentage jump erratically, stall at fixed points, or drop suddenly rather than stepping down evenly. To fix it, let the phone discharge fully until it powers off on its own, then charge continuously to 100% without interruption — this forces the IC to remap the curve against the new cell's actual capacity.