SHELL01A Doro PhoneEasy 410 Replacement Battery 3.7V 800mAh

Doro PhoneEasy 410 — 3.7V Li-ion Replacement Battery (SHELL01A)

This is a 3.7V Li-ion 800mAh (2.96Wh) replacement battery for the Doro PhoneEasy 410, PhoneEasy 410GSM, PhoneEasy 610, and PhoneEasy 409, among other models in the range. It fits the clamshell form factor these phones share and matches the OEM cell footprint at 49.93 x 40.00 x 5.60mm. Swap it in when the original cell no longer holds a charge or fails to power the phone at all.

• PhoneEasy 410, 410GSM, 610, 409 and related models: These phones share the same clamshell housing, battery bay dimensions, and connector pinout. The 3.7V nominal voltage rail is consistent across the range, so one cell covers all of them without a BMS handshake conflict.
• Bench tested on actual hardware: We ran this cell through charge and discharge cycles on the PhoneEasy platform. The BMS accepted the new cell without tripping a lockout, charge current ramped correctly from CC to CV phase, and cut off cleanly at full capacity.
• Fuel gauge recalibration on first cycle: After fitting this cell, run the phone down to auto-shutdown, then charge it uninterrupted to 100% before normal use. The PhoneEasy fuel gauge IC calibrates against the discharge curve of the cell it sees — skipping this step leaves it reading against the old degraded curve, which causes inaccurate percentage readings from day one.

Why the PhoneEasy 410 reports the wrong battery percentage after a cell swap

The fuel gauge IC on these phones uses a stored discharge curve to estimate remaining capacity. That curve was built around the original cell over months of use. A fresh 800mAh cell has a different internal resistance profile, so the IC reads the new voltage-versus-charge relationship as the old one — and gets it wrong. You will see jumpy percentages or a reading that stays stuck near 80% before dropping fast. One full discharge-to-shutdown followed by a complete uninterrupted charge resets the coulomb counter against the new cell's actual curve.

Sudden shutdown at 20–30% on the replacement cell

This is a voltage cliff issue, not a capacity problem. Under the load of an active call, the cell voltage drops sharply — and if the fuel gauge IC is still miscalibrated, the phone hits its low-voltage cutoff while the percentage display still shows 20–30%. The cutoff threshold on the PhoneEasy platform sits around 3.2V under load. Run the full recalibration cycle first. If shutdowns continue after that, check the battery contacts in the bay for oxidation — a resistive connection amplifies the voltage sag and triggers the cutoff earlier than it should.