About this replacement
Wiko Slide / N300 — 3.8V Li-ion Replacement Battery (S8321AP)
This 3.8V, 2500mAh Li-ion cell replaces the original battery in the Wiko Slide, Slide 4GB, and N300 smartphones. It matches the OEM dimensions at 78.12 × 63.55 × 4.34mm, so it seats correctly in the battery bay. Voltage and connector pinout align with the original, so the phone's charge IC sees what it expects.
- Slide, Slide 4GB, and N300 compatibility: All three models share the same battery bay dimensions, 3.8V nominal rail, and connector layout. One cell fits all three without modification or adapter.
- Bench tested on actual hardware: We cycled this cell through charge and discharge on the Slide platform. The BMS handshake completed normally, the charge IC accepted the cell without fault flags, and voltage held stable under screen-on load.
- Fuel gauge recalibration on first use: After fitting a new cell, run one full discharge down to automatic shutdown, then charge uninterrupted to 100% before using the phone normally. This gives the fuel gauge IC a clean reference curve for the new cell — without it, percentage readings can drift or spike during the first few days.
Sudden shutdown at 20–30% on the Wiko Slide after a cell swap
The Slide's fuel gauge IC holds a discharge curve learned from the original cell. A new cell with a different internal resistance profile hits a voltage cliff at a different state of charge than the old curve predicts. The phone reads 25% but the actual cell voltage has already dropped below the modem's minimum operating threshold under load. One complete discharge-charge cycle forces the coulomb counter to remap against the new cell, and the early shutdowns stop.
Device won't power on after the replacement battery sat in storage
Li-ion cells self-discharge in storage. If the cell voltage has dropped below approximately 2.5V, the BMS enters lockout mode to prevent damage and will not pass current to the phone's power rail. Plug the phone into a wall charger — not a PC USB port — and leave it for 15–20 minutes without pressing the power button. The charge IC trickle-charges the cell back above the BMS re-enable threshold, typically around 2.9V, after which the phone will boot normally.