About this replacement
LG Q6 / M700N / M700A — 3.85V Li-Polymer Replacement Battery (BL-T33)
This is a 3.85V, 3000mAh lithium-polymer cell built to the BL-T33 specification for the LG Q6 smartphone and its regional variants — M700N, M700A, and M700DSK. It fits directly into the battery bay with the original flex connector and matches the factory dimensions at 93.75 × 40.43 × 4.68mm. Capacity is rated at 11.55Wh.
- Q6 variant compatibility: The Q6 shipped across multiple regions under different model codes — M700N (global), M700A (AT&T), M700DSK (Korea) — but all share the same battery bay geometry, connector pinout, and BMS handshake protocol. One cell fits all.
- Bench tested on actual hardware: We ran this cell on an M700N unit and confirmed the BMS completed its initialisation handshake correctly, accepted a charge cycle without interruption, and held voltage within 0.05V of nominal at full charge.
- Fuel gauge recalibration on first use: On first use after installation, disable fast charging and run one complete discharge-charge cycle at standard speed. This gives the fuel gauge IC time to map the new cell's discharge curve before high-current charging begins on an uncalibrated reading.
Sudden shutdown at 20–30% on the LG Q6 after a cell swap
This is a voltage cliff issue, not a capacity fault. The fuel gauge IC still holds the discharge curve from the old degraded cell, so it reads 25% when the new cell is actually near its minimum sustainable voltage under modem or screen load. When the processor and LTE modem spike current draw simultaneously, the cell voltage drops sharply, and the protection circuit cuts power before the gauge reaches 0%. One full discharge-charge cycle at standard rate recalibrates the coulomb counter against the new cell and eliminates the premature cutoff.
USB fast charge not accepted on the first cycle after replacement
After fitting a new BL-T33, some Q6 units stay on slow charge and ignore the fast-charge handshake for the first cycle. The charge IC defaults to a conservative current profile when it does not recognise the cell's internal resistance signature from a prior cycle. Run one full standard charge first — this lets the charge IC log the cell's impedance and re-enable the fast-charge protocol. On the second plug-in, fast charging should resume at normal voltage negotiation.