HE346 Nokia 7 Plus Replacement Battery 3.85V 3700mAh

Nokia 7 Plus / TA-1046 — 3.85V Li-Polymer Replacement Battery (HE346)

This is a 3700mAh (14.25Wh) Li-Polymer cell rated at 3.85V, built to the HE346 specification for the Nokia 7 Plus (TA-1046). It replaces the original cell when capacity has dropped, the phone shuts down unexpectedly, or the battery no longer holds a useful charge. Dimensions are 88.10 × 65.55 × 4.10mm — verify clearance before installation.

• Nokia 7 Plus and TA-1046 compatibility: Both model designations share the same battery bay geometry, connector pinout, and BMS handshake protocol. The HE346 part number covers both — no hardware difference between variants at the cell level.
• Bench tested on actual hardware: We cycled this cell through charge, standby, and load conditions on a Nokia 7 Plus unit. The BMS handshake completed correctly, charge current stepped down as expected near full capacity, and no thermal events occurred during the test sequence.
• Fuel gauge recalibration on first use: After fitting this cell, disable fast charging and run one full discharge-to-charge cycle at standard rate. The fuel gauge IC on the Nokia 7 Plus is calibrated to the old cell's discharge curve. One slow cycle lets it map the new cell before fast charge pushes high current into an uncalibrated state.

Sudden shutdown at 20–30% on the Nokia 7 Plus after a cell swap

The Nokia 7 Plus uses a coulomb counter that tracks charge in and out of the cell. When a new cell goes in, the counter has no reference for where the voltage cliff on that specific cell sits. Under a sudden high-draw event — mobile data switching bands, display at full brightness, GPS active — the cell voltage can drop sharply below the BMS cutoff threshold even though the reported percentage looks safe. The phone cuts out to protect the circuit. Run two full discharge-charge cycles without fast charging to let the fuel gauge IC build an accurate state-of-charge map for the new cell.

USB-PD fast charge not accepted on first cycle after replacement

After fitting a replacement cell, some Nokia 7 Plus units fall back to standard 5V charging and refuse to negotiate the fast charge protocol. This happens because the charge IC checks cell impedance before authorising higher current — a new cell at full impedance can cause the IC to conservatively deny the USB-PD handshake. Plug into a standard 5V charger, complete one full cycle, then retry your fast charger. Most units accept the protocol normally from the second cycle onward.