WT240 Nokia 2.3 Compatible Battery 3.85V 3900mAh Li-Polymer

Nokia 2.3 / 2.3 LTE (TA-1214) — 3.85V Li-Polymer Replacement Battery (WT240)

This is a 3900mAh (15.02Wh) Li-Polymer cell at 3.85V, replacing the original WT240 in the Nokia 2.3, 2.3 LTE, and TA-1214 variants. It powers the display, processor, and wireless radios. The cell fits the WT240 footprint at 80.46 × 64.76 × 4.24mm.

• WT240 platform fit — 2.3 and 2.3 LTE: Both the standard 2.3 and the LTE variant share the same WT240 battery specification — same voltage rail, same connector pinout, and same BMS communication protocol. One cell covers the full TA-1214 board revision range.
• Bench tested on actual hardware: We cycled this cell through charge and discharge on a Nokia 2.3 unit. The BMS accepted the cell without fault codes, charge current ramped normally through CC phase, and the protection circuit tripped correctly at the low-voltage cutoff threshold.
• Fuel gauge recalibration on first use: After fitting this cell, disable fast charging for the first full discharge-charge cycle. The fuel gauge IC on the Nokia 2.3 calibrates its coulomb counter against the cell's discharge curve — running that first cycle at standard current gives the IC clean data before high-current charging begins.

Sudden shutdown at 20–30% on the Nokia 2.3 after a cell swap

This happens because the fuel gauge IC still holds the discharge curve of the old, degraded cell. The new WT240 cell has a steeper voltage-to-capacity relationship than the worn original. When the modem fires up or the screen brightness spikes, the new cell briefly sags in voltage and the IC misreads that as a low-battery cutoff — even at an indicated 25%. One full uninterrupted discharge down to automatic shutdown, followed by a full charge to 100%, resets the coulomb counter against the actual new cell curve. After that cycle, the percentage readout and cutoff behaviour stabilise.

USB fast charge not engaging on the first cycle after replacement

On the first charge after fitting a new WT240, some Nokia 2.3 units default to standard 5V/1A charging rather than negotiating the higher-current profile. The charge IC re-evaluates BMS handshake data from the new cell before allowing elevated current — this is a protective hold, not a fault. Plug in, let the first charge complete fully without interrupting it, then unplug and replug. On the second session the charge IC typically accepts the full current profile. If it still does not engage, confirm the cable supports 2A or above.