INQ Chat 3 Replacement Battery 3.7V 1500mAh Li-ion

INQ Chat 3 / Chat 3G — 3.7V Li-ion Replacement Battery

This is a 3.7V, 1500mAh Li-ion replacement battery for the INQ Chat 3 and Chat 3G smartphones. It slots into either handset and restores power where the original cell has degraded past usable capacity. Voltage and physical dimensions match the factory spec exactly: 65.23 × 41.98 × 5.21mm.

• Chat 3 and Chat 3G compatibility: Both models share the same battery bay dimensions and 3.7V supply rail. The connector pinout and BMS handshake protocol are identical across the two variants, so one cell covers both.
• Bench tested on actual hardware: We cycled this cell through charge and discharge on the Chat 3 platform. The BMS accepted the charge profile without interruption, and the protection circuit tripped correctly at the low-voltage cutoff threshold — no false trips under normal screen and radio load.
• Fuel gauge recalibration on first use: Disable any fast-charge mode for the first complete discharge-to-charge cycle after fitting this cell. The fuel gauge IC on these handsets was calibrated to the original cell's discharge curve. One full cycle at standard current lets it remap to the new cell before high-current charging begins.

Sudden shutdown at 20–30% on the INQ Chat 3 after a cell swap

The Chat 3's fuel gauge IC holds a discharge curve learned from the original cell. A new cell has a different internal resistance profile, so the voltage reading the IC sees diverges from the actual state of charge. Under modem or display load — both high-current draws on this platform — the cell voltage dips sharply at a point the IC has not yet mapped. The phone interprets that dip as a hard low-voltage event and shuts down, even though usable charge remains. One full discharge-to-zero then a full charge at standard current resets the coulomb counter and eliminates most of these false shutoffs.

INQ Chat 3 reporting erratic or frozen battery percentage after replacement

Percentage jumping from 60% to 30% in minutes — or locking at one figure for hours — points to the fuel gauge IC reading from a stale discharge table. The IC does not automatically discard its stored curve when a new cell is fitted. It keeps projecting percentage against the old degraded cell's behaviour. Run the phone down until it shuts itself off at the low-voltage cutoff (typically around 3.0–3.2V terminal voltage), then charge uninterrupted to 100%. That single cycle forces the IC to recalculate against the new cell and stabilises the percentage readout.