Huawei Ascend P8 Compatible Battery HB3447A9EBW 3.8V 2600mAh

Huawei Ascend P8 — 3.8V Li-Polymer Replacement Battery (HB3447A9EBW)

This is a 3.8V, 2600mAh Li-Polymer cell replacement for the Huawei Ascend P8 smartphone. It fits the GRA-L09, GRA-TL10, and related Ascend P8 variants. The battery installs directly against the original flex connector and BMS contact points.

• Ascend P8 GRA variant compatibility: The GRA-L09 and GRA-TL10 share the same physical battery bay, connector pitch, and 3.8V charge cutoff threshold. Both use the HB3447A9EBW cell specification, so one cell fits the full GRA sub-family without modification.
• Bench tested on actual hardware: We cycled this cell through charge and discharge on an Ascend P8 unit. The BMS accepted the cell on first connection, completed a full charge to 4.35V, and triggered low-voltage cutoff cleanly at the expected floor. No false capacity readings on first cycle — though the fuel gauge IC will need one full cycle to lock onto the new cell curve.
• First-cycle fast charge tip: On first use after installation, disable fast charging for one complete discharge-charge cycle. This lets the fuel gauge IC recalibrate against the new cell's discharge curve before high-current charging pushes current into an uncalibrated cell — which can cause the percentage display to jump erratically in early use.

Why the Ascend P8 reports wrong battery percentage after a cell swap

The Ascend P8 uses a coulomb counter in its fuel gauge IC to track remaining capacity. That counter is calibrated to the discharge curve of the original cell. When a new cell goes in, the stored curve no longer matches actual voltage-versus-capacity behaviour, so the reported percentage drifts — sometimes reading 40% and cutting off, sometimes jumping between values. The fix is one complete discharge from 100% down to automatic shutdown, followed by a full uninterrupted charge to 100%. After that single cycle, the fuel gauge re-anchors its model to the new cell and percentage reporting stabilises.

Sudden shutdown at 20–30% on the replacement cell

This happens when the modem, display, or a background process pulls a brief high-current spike and the cell voltage drops sharply under load — crossing the BMS cutoff threshold even though the displayed percentage still looks safe. It is a voltage sag issue, not a capacity issue. On the Ascend P8, the modem radio during a call or LTE handoff is the most common trigger. Run one full calibration cycle first. If shutdowns persist, check that the battery flex cable is fully seated — a partially connected cell raises internal resistance and makes voltage sag worse under load.