I-Mate SmartphoneII SV10B Replacement Battery 3.7V 950mAh

I-Mate SmartphoneII — 3.7V Li-ion Replacement Battery (SV10B / SV16A)

This 3.7V, 950mAh Li-ion battery replaces the original cell in the I-Mate SmartphoneII. It fits the SmartphoneII directly, using OEM part numbers SV10B and SV16A. Swap it in when the original cell no longer holds a charge or the device shuts down unexpectedly.

• SmartphoneII fit: The SV10B and SV16A share the same connector pinout and physical footprint on the SmartphoneII motherboard. The BMS on this cell matches the charge termination voltage the SmartphoneII's charge IC expects — 4.2V — so the device charges and reports state-of-charge correctly once the fuel gauge IC recalibrates.
• Bench tested on actual hardware: We cycled this cell through full charge and discharge on a SmartphoneII platform. The BMS held cut-off at 3.0V on discharge and accepted CC/CV charge without tripping protection. No false full-charge events were recorded across three consecutive cycles.
• Fuel gauge recalibration on first use: After installation, disable any fast-charge accessory for the first complete discharge-to-charge cycle. This gives the SmartphoneII's fuel gauge IC time to map the new cell's discharge curve before high-current charging is applied to an uncalibrated cell.

Why the SmartphoneII reports wrong battery percentage after a cell swap

The SmartphoneII uses a fuel gauge IC that builds its capacity model from previous charge-discharge cycles. When a new cell goes in, the IC still references the old cell's learned curve. Until one full discharge and recharge cycle completes, the percentage reading will lag or jump. This is not a fault with the replacement cell — it is the IC recalibrating its coulomb counter against the new chemistry baseline. Run one full cycle from 100% down to automatic shutdown, then charge fully uninterrupted.

Sudden shutdown at 20–30% on the replacement cell

This happens when the fuel gauge IC's state-of-charge estimate diverges from the cell's actual voltage. Under modem or screen load, the cell voltage drops faster than the uncalibrated gauge predicts, hitting the hardware protection threshold before the OS registers low battery. The BMS trips at approximately 3.0V per cell and cuts output to protect the cell. One full supervised discharge-charge cycle resets the gauge's internal reference and eliminates premature shutdowns.