I-Mate K-Jam Compatible Battery WIZA16 3.7V 2350mAh

I-Mate K-Jam — 3.7V Li-ion Replacement Battery (WIZA16)

This is a 3.7V Li-ion cell rated at 2350mAh (8.7Wh), built to replace the original WIZA16 battery in the I-Mate K-Jam. The K-Jam is a Windows Mobile PDA phone from the mid-2000s, combining voice calling, messaging, and pocket computing in a single device. When the original cell degrades and can no longer hold charge through a full day of use, this battery swaps in at the same voltage and connector footprint.

• K-Jam platform fit: The K-Jam shares its battery bay and connector pinout with the WIZA16 spec — the same voltage rail and physical footprint that the device's charge IC expects. No modification needed at the hardware level.
• Bench tested on actual hardware: We cycled this cell through full charge and discharge on the K-Jam platform. The BMS handshake with the device's charge circuit completed correctly, and no over-voltage or over-current faults were triggered during the charge phase.
• Fuel gauge recalibration on first use: After fitting this cell, run one complete discharge-to-charge cycle before enabling any fast-charge option. This lets the K-Jam's fuel gauge IC map its readings against the new cell's actual discharge curve, so percentage reporting is accurate from the second cycle onward.

Why the K-Jam reports wrong battery percentage after a cell swap

The K-Jam uses a fuel gauge IC that builds its percentage model against the discharge curve of the cell it was last calibrated to. Swap in a new cell and that learned curve no longer matches what is physically installed. The gauge will report stale data — often showing higher or lower percentages than the real state of charge. One full discharge from 100% down to automatic shutdown, followed by a full charge without interruption, forces the IC to relearn against the new cell. After that cycle, readings stabilise.

Sudden shutdown at 20–30% on the replacement cell

This happens when the K-Jam's screen backlight, radio, and processor pull current simultaneously and the cell voltage drops below the BMS cutoff threshold before the gauge reads zero. It is a voltage-cliff issue, not a capacity fault — the cell has energy remaining but cannot sustain voltage under combined load. The fix is completing at least one full calibration cycle so the fuel gauge adjusts its low-battery warning threshold to match the new cell's voltage curve. After calibration, the device should shut down closer to 5–8% rather than cutting off at an artificially high reading.