BLP837 Oppo Realme 8 Pro Compatible Battery 3.87V 4300mAh

Oppo Realme 8 Pro — 3.87V Li-Polymer Replacement Battery (BLP837)

The BLP837 is a 4300mAh Li-Polymer cell at 3.87V, replacing the original battery in the Realme 8 Pro smartphone. It restores power to the display, processor, and modem when the original cell has degraded through repeated charge cycles. Capacity is rated at 16.64Wh and dimensions match the original at 89.80 × 62.50 × 4.40mm.

• Realme 8 Pro fitment: The BLP837 uses the same connector pinout and cell footprint as the factory unit. The BMS communicates over the same data line the Realme 8 Pro's charge IC expects, so the phone recognises the pack without throwing a battery authentication warning.
• Bench tested on actual hardware: We cycled this cell through charge and load sequences on the bench. The BMS held protection thresholds correctly — no premature cutoff under screen-on modem load, and overvoltage cutoff triggered cleanly at the top of the charge curve.
• First-cycle fast charge handling: On first use after installation, disable SUPERVOOC fast charging for one full discharge and recharge cycle. This lets the fuel gauge IC map the new cell's discharge curve before high-current charging pushes current into an uncalibrated coulomb counter.

Sudden shutdown at 20–30% on the Realme 8 Pro after a cell swap

The Realme 8 Pro's fuel gauge IC stores a learned discharge curve from the old cell. When a new BLP837 goes in, that stored curve no longer matches the new cell's actual voltage-versus-capacity profile. Under modem or display load, the cell voltage drops faster than the IC predicts, hitting the hardware cutoff while the OS still shows 20–30% remaining. One full slow-charge cycle lets the coulomb counter recalibrate against the real curve and eliminates most of these shutdowns.

SUPERVOOC fast charge not activating on the first cycle after replacement

SUPERVOOC handshake requires the charge IC to confirm BMS state before stepping voltage up. On a fresh cell that has never completed a full cycle, the BMS presents higher internal impedance, and the charge IC falls back to standard 5V/2A input as a protection measure. This is not a fault — it is the charge IC behaving correctly. Complete one full standard charge to 100%, allow the pack to discharge naturally, then reconnect the SUPERVOOC adapter and the fast-charge handshake will proceed normally.