BL-05 Nokia E11 Replacement Battery 3.7V 1200mAh Li-ion

LAMTAM Nokia E11 / E16 / LT826 / LT828 — 3.7V Li-ion Replacement Battery (BL-05)

This is a 3.7V, 1200mAh Li-ion cell sourced under the LAMTAM X-Longer series to replace the Nokia BL-05 battery. It fits the Nokia E11, E16, LT826, and LT828. Dimensions are 53.00 × 33.90 × 5.70mm — match these against your existing cell before installing.

• E11 / E16 / LT826 / LT828 platform fit: These four models share the same BL-05 form factor, 3.7V single-cell architecture, and connector pinout. One cell fits all four without modification.
• Bench tested on actual hardware: We ran this cell through full charge and load cycles on compatible hardware. The BMS held cutoff correctly at low voltage and accepted charge current without triggering protection lockout mid-cycle.
• Fuel gauge recalibration on first use: On first installation, disable fast charging and run one complete discharge-to-charge cycle at standard current. This lets the phone's fuel gauge IC map the new cell's discharge curve before high-current charging begins on an uncalibrated cell.

Sudden shutdown at 20–30% on the E11 after a cell swap

The Nokia E11's fuel gauge IC stores a discharge curve from the original cell in its coulomb counter. A new cell with different internal impedance causes the gauge to report 20–30% remaining when the actual cell voltage has already dropped near the BMS cutoff threshold. Under modem transmit load or screen brightness spikes, the voltage dips below 3.4V and the phone shuts down instantly. Run two full discharge-charge cycles at standard charge current — the fuel gauge IC will relearn the curve and the shutdowns will stop.

Phone shows wrong battery percentage after fitting the BL-05 replacement

After swapping to a new cell, the coulomb counter is still calibrated to the old cell's capacity and impedance profile. It will report inaccurate percentages — often jumping several points or freezing — until it completes a full cycle. Charge the phone to 100% via the standard charger, allow it to drain fully until shutdown, then charge uninterrupted to 100% again. After that cycle, percentage readings stabilise against the new 1200mAh cell at 3.7V nominal.