Honor Play 40 HB466594EGW Replacement Battery 3.89V 5100mAh

Honor Play 40 / WDY-AN00 — 3.89V Li-Polymer Replacement Battery (HB466594EGW)

This is a 5100mAh Li-Polymer cell at 3.89V, sourced to match the OEM spec for the Honor Play 40 (WDY-AN00). It replaces a degraded original battery that no longer holds charge through a normal day. Physical dimensions are 92.70 × 64.90 × 4.70mm — measure your existing cell before fitting if the back cover shows any swelling.

• Play 40 / WDY-AN00 fitment: Both model references share the same battery bay geometry, connector pinout, and BMS handshake protocol. The HB466594EGW part number covers the full variant range — the fuel gauge IC on both boards reads the same cell identification signal.
• Bench tested on actual hardware: We cycled this cell through charge and discharge on the Play 40 board, confirmed BMS handshake on first connection, and verified the charge IC accepted the full 5100mAh load without triggering a protection cutoff.
• Fuel gauge recalibration on first use: After installation, disable fast charging and run one complete discharge down to auto-shutdown, then charge to 100% on standard current. This gives the coulomb counter a clean reference curve before fast charge pushes high current into an uncalibrated cell.

Sudden shutdown at 20–30% on the Honor Play 40 after a cell swap

A new Li-Polymer cell has a slightly different discharge curve than the worn cell the fuel gauge IC was calibrated against. Under heavy load — modem transmission, screen at full brightness, GPS active — the cell voltage drops sharply at around 3.5V while the gauge still reads 20–30%. The phone interprets this as a valid state of charge until voltage collapses below the BMS cutoff threshold. One full discharge-charge cycle on standard current resets the coulomb counter and eliminates most of these early shutdowns.

USB-PD fast charge not activating on the first cycle after replacement

Honor's fast charge protocol requires the charge IC to negotiate with the BMS before stepping up current. On a fresh cell, the BMS starts in a conservative low-current mode until it confirms cell voltage stability over at least one partial charge cycle. Plugging in and seeing only a standard 5W charge rate on the first session is expected behaviour — not a fault with the cable or adapter. After the first full charge completes, disconnect and reconnect the charger; the fast charge handshake should activate and the charge IC will step up to the rated current.