Nokia 3.1 HE351 Replacement Battery 3.85V 2900mAh

Nokia 3.1 / TA-1049 / TA-1057 / TA-1070 — 3.85V Li-Polymer Replacement Battery (HE351)

This is a 3.85V, 2900mAh Li-Polymer replacement battery for the Nokia 3.1 smartphone. It fits the TA-1049, TA-1057, and TA-1070 variants alongside the standard 3.1 handset. The HE351 part number matches the OEM cell these models shipped with.

• TA-1049, TA-1057, TA-1070 compatibility: All three Nokia 3.1 variants share the same battery bay dimensions, connector pinout, and charge IC handshake. The HE351 slot physically and electrically into all of them without modification.
• Bench tested on actual hardware: We cycled this cell on a Nokia 3.1 unit and logged the BMS response across charge and discharge. The protection circuit triggered correctly at the low-voltage cutoff, and the charge IC accepted the cell without fault flags on subsequent cycles.
• Fuel gauge recalibration on first use: On first use after installation, disable fast charging for one complete discharge-charge cycle. This lets the fuel gauge IC map the new cell's discharge curve before the charge IC pushes higher current into an uncalibrated cell — preventing erratic percentage readings from day one.

Sudden shutdown at 20–30% on the Nokia 3.1 after a cell swap

This is a voltage cliff issue, not a defective cell. The modem and display together pull enough current to drop the cell voltage below the BMS cutoff threshold — even when the fuel gauge still reads 20–30%. The fuel gauge IC is still calibrated to the old cell's discharge curve, so it overestimates remaining capacity at moderate loads. Run one full discharge to automatic shutoff, then charge uninterrupted to 100% without interruption. After that cycle, the coulomb counter recalibrates and the shutdowns stop.

USB fast charge not triggering after replacement on the Nokia 3.1

On the first charge cycle after fitting a new cell, the Nokia 3.1's charge IC sometimes stays in trickle mode rather than stepping up to fast charge. This happens because the BMS on a fresh cell starts with a low-state flag that tells the charge IC to proceed cautiously. Plug in, leave the phone alone for 10–15 minutes without waking the screen, and the charge IC will negotiate the higher current rate once it clears the initial cell-check handshake. Fast charging resumes normally from the second cycle onward.