Verizon SCH-U680 Replacement Battery 3.7V 1300mAh Li-ion

Verizon SCH-U680 Convoy 3 — 3.7V Li-ion Replacement Battery

This 3.7V 1300mAh Li-ion cell fits the Samsung SCH-U680 and SCH-U680MAV, sold under the Verizon Convoy 3 name. It slots into the standard battery bay and connects to the same contact pads as the original cell. Voltage and capacity match the OEM spec — 3.7V nominal, 1300mAh (4.81Wh).

• SCH-U680 / Convoy 3 platform fit: The U680, U680MAV, and SCHU680MAV all share the same battery bay dimensions (52.30 × 33.20 × 6.50mm), contact layout, and 3.7V rail. One cell covers the full variant range without modification.
• Bench tested on actual hardware: We cycled this cell through the U680's charge IC and confirmed the BMS accepted the charge handshake without error flags. Discharge held stable voltage through the phone's modem and display load.
• Fuel gauge recalibration on first use: After installing this cell, run one full discharge to shutdown and charge to 100% before normal use. The U680's fuel gauge IC is calibrated to the old cell's discharge curve — one full cycle corrects the coulomb counter and prevents erratic percentage readings.

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

The U680's fuel gauge IC reads state-of-charge against a stored discharge curve from the original cell. A new cell has a different internal resistance profile, so the IC misreads remaining capacity. Under modem or backlight load, actual cell voltage drops faster than the gauge expects, and the phone cuts power before the display shows low battery. One full discharge-to-shutdown cycle followed by a complete charge lets the coulomb counter reset against the new cell's actual curve. After that cycle, shutdowns below 15% are normal — shutdowns at 25–30% should stop.

Phone won't power on after the replacement cell sat in storage

Li-ion cells self-discharge during storage. If this battery sat unused for several months before installation, the cell voltage may have dropped below 2.5V — the threshold at which the BMS locks out to prevent damage. The Convoy 3 will show no response at all: no boot screen, no charging indicator. Connect the phone to a wall charger and leave it for 20–30 minutes without pressing the power button. The charge IC trickle-charges the cell back above the 2.8V BMS re-enable threshold, after which the phone will boot normally.