About this replacement
Wiko View3 Pro / View 4 Lite / Y81 — 3.8V Li-Polymer Replacement Battery (TPJ18K07P)
This is a 3.8V, 3900mAh lithium-polymer battery that replaces the original TPJ18K07P cell in the Wiko View3 Pro, View 4 Lite, and Y81 smartphones. It restores full charging function to devices where the original cell has degraded or failed to hold a charge. Capacity matches the factory specification: 3900mAh / 14.82Wh.
- View3 Pro, View 4 Lite, and Y81 fitment: These three models share the same battery bay dimensions and connector pinout. The TPJ18K07P BMS handshake is compatible across all three platforms — the charge IC reads the same protection circuit on each.
- Bench tested on actual hardware: We cycled this cell on the View3 Pro charge IC and confirmed BMS cutoff triggers correctly at the low-voltage threshold. The protection circuit tripped as expected under overcurrent conditions and reset without issue.
- Fuel gauge recalibration on first use: After installation, disable fast charging and run one full discharge-charge cycle at standard current. This lets the fuel gauge IC map the new cell's discharge curve before high-current charging pushes into an uncalibrated coulomb counter.
Sudden shutdown at 20–30% on the replacement cell
This is a voltage cliff problem, not a capacity fault. When the modem transmits or the screen pushes peak brightness, load current spikes sharply. A new cell with an uncalibrated fuel gauge IC shows 25% state-of-charge on screen while the actual cell voltage drops below the BMS cutoff threshold under load — triggering an abrupt shutdown. One full discharge-to-shutdown, then full charge cycle recalibrates the coulomb counter. After that, reported percentage and actual cell voltage track together correctly.
USB fast charge not activating after battery swap
On the first charge cycle after a cell replacement, the charge IC defaults to standard 5V / 1A input until it completes an internal handshake with the new BMS. This is a safety hold — not a fault with the battery or charger. Complete one full standard-current charge cycle first. Fast charging typically activates automatically from the second cycle onward once the charge IC registers the new cell as stable.