Virgin Mobile Venture VM2045 Replacement Battery 3.7V 1500mAh

Virgin Mobile Venture VM2045 — 3.7V Li-ion Replacement Battery

This is a 3.7V, 1500mAh Li-ion replacement battery for the Virgin Mobile Venture VM2045 smartphone. It slots into the same bay as the original cell and connects to the same charge IC and fuel gauge circuit. Capacity is rated at 1500mAh (5.55Wh), matching the factory specification.

• Venture VM2045 cell compatibility: The VM2045 runs a single-cell 3.7V Li-ion configuration with a direct BMS connection to the board. The replacement cell carries the same nominal voltage and physical footprint — 64.30 × 49.50 × 4.50mm — so the connector seats without modification and the charge IC sees the expected impedance profile on first contact.
• Bench tested on actual hardware: We cycled this cell through charge and load on a VM2045-class board. The BMS accepted the new cell without a handshake error, charge current ramped normally through CC/CV stages, and the protection circuit tripped correctly at the low-voltage cutoff threshold under a sustained load.
• Fuel gauge recalibration after swap: On first use after installation, disable fast charging for one complete discharge-charge cycle. The fuel gauge IC is still calibrated to the discharge curve of the old cell. Running one full cycle on standard charge current lets the coulomb counter reset its reference points against the new cell before any high-current charge profile is applied.

Why the VM2045 reports wrong battery percentage after a cell swap

The VM2045 uses a fuel gauge IC that tracks battery state by counting charge in and out — a process called coulomb counting. When you install a new cell, the IC still holds the learned discharge curve of the old, degraded battery. The percentage shown on screen reflects the old curve, not the actual state of the new cell. One full discharge down to automatic cutoff followed by a full charge resets the reference and brings the reported percentage back in line with actual capacity.

Sudden shutdown at 20–30% remaining on the replacement cell

This happens when the cell voltage drops sharply under load — a voltage cliff — before the fuel gauge reaches the predicted cutoff point. On the VM2045, the modem radio and screen together can pull current that causes a fresh, uncalibrated cell to sag below the BMS cutoff threshold even while the OS still reports charge remaining. The fix is the same recalibration cycle: run the phone down until it shuts off on its own, then charge uninterrupted to 100% at standard current. After one full cycle, the fuel gauge IC adjusts its curve and the premature shutdowns stop. If the problem continues past two full cycles, check that the battery connector is fully seated — a high-resistance contact causes the same voltage sag symptom.