AT&T Maven 3.8V Replacement Battery 2000mAh Li-Polymer

AT&T Maven / Maven 4G — 3.8V Li-Polymer Replacement Battery

This is a 3.8V, 2000mAh (7.6Wh) lithium-polymer cell built to fit the AT&T Maven and Maven 4G smartphones. It replaces the original battery when capacity has dropped, the phone shuts down unexpectedly, or the cell no longer holds a useful charge. Physical dimensions are 88.91 × 34.73 × 4.25mm — confirm these against your original before installing.

• Maven and Maven 4G compatibility: Both variants share the same battery bay dimensions, connector pinout, and 3.8V nominal voltage rail. A single cell fits both without modification.
• Bench tested on actual hardware: We cycled the cell through charge and discharge on a calibrated rig, confirming BMS cutoff behaviour at low-voltage threshold and stable voltage delivery under modem-load simulation across the full discharge curve.
• Fuel gauge recalibration on first use: After installation, disable fast charging and run one full discharge down to automatic shutdown, then charge uninterrupted to 100%. This gives the phone's fuel gauge IC a complete reference curve against the new cell before it starts reporting reliable percentages.

Sudden shutdown at 20–30% on the replacement cell

This is a voltage cliff problem, not a capacity problem. At 20–30% state-of-charge, the new cell's voltage drops under modem or screen load faster than the old degraded cell the fuel gauge IC was calibrated to. The phone's power IC interprets the voltage sag as a critical low-battery event and triggers an immediate shutdown. One full discharge-to-shutdown followed by a full uninterrupted charge resets the coulomb counter reference and typically resolves the early cutoff.

Phone not powering on after the battery sat discharged in storage

Li-polymer cells that drop below approximately 2.5V per cell trigger a BMS lockout to prevent damage from deep discharge. If the Maven won't respond to the power button after sitting unused, connect it to a wall charger — not a PC USB port — and leave it for 20–30 minutes without pressing anything. The charge IC will trickle current into the cell until voltage recovers above the BMS re-enable threshold, at which point the phone will begin a normal boot cycle.