I-Mate Ultimate 6150 Compatible Battery 3.7V 1600mAh

I-Mate Ultimate 6150 / 8150 Series — 3.7V Li-Polymer Replacement Battery (WDSO080204873)

This 3.7V, 1600mAh lithium-polymer battery replaces the original cell in the I-Mate Ultimate 6150, Ultimate 8150, and Ultimate 8150 WIFI 3G smartphones. It matches the OEM voltage and capacity spec directly, with physical dimensions of 67.52 × 44.11 × 4.74mm. Order this when the original battery no longer holds a charge or the device shuts down unexpectedly under load.

• Ultimate 6150, 8150, and 8150 WIFI 3G fitment: These three models share the same battery bay dimensions, connector pinout, and 3.7V charge rail. The BMS communication protocol is identical across the series, so one cell covers all three without modification.
• Bench tested on actual hardware: We ran this cell through charge and discharge on the I-Mate platform. The BMS accepted the cell without fault flags, charge termination triggered correctly at 4.2V, and low-voltage cutoff engaged at the expected threshold rather than dropping the device mid-use.
• First-cycle calibration on the Ultimate platform: On first use after installation, disable fast charging for one complete discharge-charge cycle. This lets the fuel gauge IC recalibrate against the new cell's discharge curve before high-current charging pushes into an uncalibrated cell — reducing percentage jump errors early on.

Sudden shutdown at 20–30% on the replacement cell

This happens because the fuel gauge IC was calibrated to the discharge curve of the old, degraded cell. The new cell has a steeper voltage drop near depletion under modem or screen load, and the IC misreads remaining capacity. When the cell voltage drops below the BMS cutoff threshold — around 3.0V under load — the device shuts off even though the OS still shows charge remaining. One full discharge-to-shutdown followed by an uninterrupted charge to 100% forces the coulomb counter to re-anchor to the new cell's actual curve.

Phone reports wrong battery percentage after cell swap

The fuel gauge IC stores a learned discharge profile from the original cell. A new 1600mAh cell with a different internal resistance will read as a different curve, causing the percentage to jump or plateau at incorrect values. The fix is a full calibration cycle: drain the device until it powers off on its own, then charge uninterrupted to 100% without using the device. After one complete cycle the IC resets its reference points against the new cell and percentage reporting stabilises.