Aligator D100 Replacement Battery 3.7V 900mAh Li-ion

Aligator D100 — 3.7V Li-ion 900mAh Replacement Battery

This is a 3.7V Li-ion replacement battery for the Aligator D100 smartphone. It replaces a failed or degraded original cell and restores the phone to normal operation for calls, messaging, and basic functions. Capacity is 900mAh (3.33Wh), matching the original cell specification.

• Aligator D100 fitment: The D100 uses a compact 46.20 x 34.14 x 5.68mm cell format with a low-current 3.7V rail. The connector pinout and BMS handshake are specific to this housing — do not substitute a higher-capacity cell from a different model even if the footprint looks close.
• Bench tested on actual hardware: We cycled this cell through charge and discharge while monitoring BMS cutoff thresholds. The protection circuit tripped correctly at the low-voltage floor and accepted charge without error flags on the fuel gauge IC.
• Fuel gauge recalibration on first use: On first use after installation, disable fast charging and run one full discharge-to-charge cycle before relying on the percentage readout. This lets the fuel gauge IC map its coulomb counter against the new cell's actual discharge curve before any high-current charging session.

Sudden shutdown at 20–30% on the Aligator D100 after a cell swap

This happens when the fuel gauge IC is still calibrated to the old cell's discharge curve. The new cell hits a voltage cliff — it cannot sustain rail voltage under combined modem and screen load — before the reported percentage reaches zero. The phone interprets the voltage drop as a hard fault and cuts off. One complete discharge cycle from 100% to automatic shutdown, followed by a full charge, resets the coulomb counter to the new cell's actual capacity curve.

Phone not powering on after the replacement cell sat in storage

Li-ion cells self-discharge in storage. If the cell voltage drops below approximately 2.5V per cell, the BMS enters lockout mode to prevent charging a critically depleted cell at full current. The phone shows nothing — no charge indicator, no boot screen. Connect to a wall charger rated at least 5V/1A and leave it for 20–30 minutes without pressing the power button; the charge IC uses a trickle pre-charge path to recover the cell to a safe voltage before the BMS releases and normal charging begins.