OnePlus 5 BLP637 Replacement Battery 3.85V 3200mAh

OnePlus 5 / 5T Series — 3.85V Li-Polymer Replacement Battery (BLP637)

This is a 3.85V, 3200mAh Li-Polymer cell that replaces the original BLP637 battery in the OnePlus 5 and 5T lineup. It fits the OnePlus 5, 5 Dual SIM, A5000, and 5T Star Wars Limited Edition, among other variants. Swap it in when the original cell can no longer hold a charge or causes unexpected shutdowns.

• OnePlus 5 and 5T platform fit: These models share the same battery bay dimensions, connector pinout, and BMS handshake protocol. The BLP637 spec covers the full voltage rail these boards expect — 3.85V nominal with the same charge termination voltage the PMIC is configured for.
• Bench tested on actual hardware: We ran this cell through charge and discharge cycles on a OnePlus 5 unit. The BMS accepted the cell without triggering a fault, and the charge IC completed a full cycle without interruption. Coulomb counter registration was clean after one full discharge.
• Fuel gauge recalibration on first use: On first use after installation, disable WARP Charge or fast charging for one complete discharge-charge cycle. This lets the fuel gauge IC map the new cell's discharge curve before high-current charging pushes current into an uncalibrated register — otherwise percentage readings drift early.

Sudden shutdown at 20–30% on the OnePlus 5 after a cell swap

This happens because the fuel gauge IC is still using the discharge curve it learned from the old, degraded cell. When modem activity or screen brightness spikes current draw, the new cell's actual voltage briefly dips below the shutdown threshold — even though the reported percentage looks safe. The phone cuts out to protect the board, not because the cell is faulty. Run one full discharge to 1% and a complete charge to 100% with fast charging off, and the coulomb counter will re-anchor to the new cell's curve.

WARP Charge not activating on the first cycle after replacement

OnePlus's proprietary fast charge protocol requires the charge IC to authenticate the cell's BMS response before switching to high-current mode. On the first cycle after a swap, the IC often defaults to standard 5V charging until it completes one handshake. Plug into the original OnePlus charger and cable — third-party cables with high-resistance data lines block the authentication signal entirely. After the first full cycle completes, WARP Charge should activate normally on subsequent connections.