OnePlus 7T BLP743 Replacement Battery 3.85V 3700mAh

OnePlus 7T Series — 3.85V Li-Polymer Replacement Battery (BLP743)

This is a 3.85V, 3700mAh (14.25Wh) Li-Polymer replacement battery for the OnePlus 7T smartphone. It fits models HD1905, HD1901, and HD1903 — all variants of the 7T lineup that share the BLP743 cell format. Swap it in when the original cell no longer holds charge or has swollen beyond safe use.

• 7T variant compatibility: The HD1905, HD1901, and HD1903 share the same internal battery bay dimensions, connector pinout, and BMS communication protocol — that is why one cell covers all three. The BLP743 format fits each without modification.
• Bench tested on actual hardware: We ran this cell on a HD1901 unit, monitored BMS handshake at power-on, and confirmed the charge IC accepted the cell without fault codes. Capacity read-back aligned with the rated 3700mAh within standard tolerance.
• Fuel gauge recalibration on first use: After installation, disable Warp Charge and run one full discharge-charge cycle at standard 5V/2A. This lets the fuel gauge IC map the new cell's discharge curve before high-current charging pushes current into an uncalibrated coulomb counter — preventing erratic percentage readings from the first hour of use.

Sudden shutdown at 20–30% on the BLP743 replacement cell

This happens when the fuel gauge IC is still calibrated to the old cell's discharge curve. The new cell hits a steeper voltage cliff under display or modem load than the old curve predicts, and the system shuts down before the reported percentage reaches zero. It is not a fault in the cell itself. Run one complete discharge to auto-off, then charge uninterrupted to 100% — after that cycle, the coulomb counter resets its reference points and the shutdowns stop.

Warp Charge not activating on first cycle after replacement

On the first charge after a cell swap, the OnePlus charge IC runs a verification pass against the new BMS before enabling high-current Warp Charge. If the BMS has not completed its initial handshake — which requires at least one partial discharge — the phone falls back to standard 5V charging silently, with no notification. Discharge the phone to below 15% before plugging in for the second time. Warp Charge typically re-engages at that point, and the charging brick LED will confirm the high-current mode is active.