About this replacement
Doro PhoneEasy 338 / 345 / 342 — 3.7V Li-ion Replacement Battery (01.10.CAREP0103)
This 3.7V 800mAh Li-ion battery replaces the original cell in the Doro PhoneEasy 338, PhoneEasy 342, PhoneEasy 345, and HandlePlus 334, along with nine additional compatible models. It restores power to devices where the original battery no longer holds charge through a normal day of use. Dimensions are 53.70 × 36.70 × 4.80mm — confirm these against the existing cell before fitting.
- PhoneEasy and HandlePlus compatibility: These models share the same battery bay dimensions, connector orientation, and 3.7V single-cell architecture. No BMS handshake is required — the charge IC on the phone communicates directly with the cell through a standard two-contact configuration.
- Bench tested on actual hardware: We ran this cell through full charge and discharge cycles on the PhoneEasy platform. The BMS protection circuit triggered correctly at the low-voltage cutoff, and charge acceptance from the phone's onboard IC was normal throughout.
- Fuel gauge recalibration on first use: After fitting, allow one complete discharge down to automatic shutoff followed by a full uninterrupted charge. The phone's fuel gauge IC calibrates its reference curve against the new cell during this cycle — skipping it causes the percentage indicator to misread capacity from day one.
Why the PhoneEasy 338 reports wrong battery percentage after a cell swap
The phone uses a simple fuel gauge IC that estimates remaining charge based on a stored discharge curve from the original cell. A new cell has a different internal resistance and discharge profile — the IC does not detect the swap and keeps referencing the old curve. This mismatch produces percentage readings that jump, stall, or sit higher than actual charge. One full discharge-to-shutoff and uninterrupted recharge cycle resets the IC's reference and brings the readout back into alignment.
Sudden shutdown at 20–30% on the PhoneEasy after replacement
This happens when the cell voltage drops sharply under the load of an active call or screen wake — a behaviour called voltage cliff. The phone's protection circuit reads the voltage drop as a low-battery cutoff and shuts down, even though the percentage indicator showed charge remaining. It is more common in the first few cycles on a new cell before the fuel gauge IC has a calibrated curve to work from. After one full discharge-charge cycle, the IC tracks the voltage profile more accurately and shutdowns at false percentages stop.