Cricket Ascend Q Replacement Battery 3.7V 1800mAh

Cricket Ascend Q / M660 — 3.7V Li-ion Replacement Battery

This 3.7V, 1800mAh Li-ion cell replaces the original battery in the Cricket Ascend Q and M660 smartphones. It restores calling, messaging, and mobile data functions when the original cell has degraded or stopped holding a charge. Dimensions are 51.30 × 50.80 × 5.60mm — confirm fitment against your existing cell before installation.

• Ascend Q and M660 compatibility: Both models share the same battery bay dimensions, connector pinout, and charge IC handshake protocol. One cell covers both platforms without modification.
• Bench tested on actual hardware: We ran the cell through charge, discharge, and modem-load cycles. The BMS held within spec voltage limits and did not trigger overcurrent cutoff during screen-on LTE traffic bursts.
• Fuel gauge recalibration on first cycle: On first use after installation, disable fast charging and run one full discharge down to automatic shutoff, then charge uninterrupted to 100%. This gives the fuel gauge IC a clean reference curve against the new cell before high-current charging begins.

Sudden shutdown at 20–30% on the replacement cell

A new cell has a different discharge curve than the worn cell the fuel gauge IC was calibrated against. The IC thinks there is charge remaining, but the cell voltage drops below the modem's minimum threshold under load and the phone cuts off. This is not a defective battery — it is an uncalibrated coulomb counter. One full discharge-to-shutoff and uninterrupted recharge cycle resets the reference. After that cycle, shutdowns at mid-percentage should stop.

Phone warm near the battery during the first few charges

A new cell starts with higher internal impedance than a conditioned cell. The charge IC pushes current into that resistance, and some energy dissipates as heat. This is normal for the first two to three charge cycles as the cell conditions and impedance drops. If the back of the phone becomes hot to the touch — above what feels like 40°C — remove the battery and let it cool before continuing. After the first three cycles, charge temperature should normalise.