About this replacement
Asus M530 Series — 3.7V Li-ion Replacement Battery (SBP-10)
This is a 3.7V, 1300mAh Li-ion cell built to fit the Asus M530, M530w, M536, and M530E smartphones. It slots into the original battery bay and connects via the factory ribbon contact. Capacity matches the original spec — no inflated numbers.
- M530 series compatibility: The M530, M530w, M536, and M530E share the same battery bay dimensions and contact layout. All four models use the SBP-10 footprint — 52.20 × 38.70 × 6.70mm — with the same three-contact ribbon connector and identical voltage rail. One cell covers the range.
- Bench tested on actual hardware: We cycled this cell through charge and load draws that mirror screen-on, call, and idle states. The BMS held cutoff cleanly at the low-voltage threshold and accepted a full charge without thermal flags.
- Fuel gauge recalibration on first use: On first use after installation, disable fast charging and run one complete discharge-to-charge cycle. The fuel gauge IC on the M530 calibrates its coulomb counter against the cell's actual discharge curve. Skipping this step is the main reason the phone reports a wrong percentage after a swap.
Why the M530 reports wrong battery percentage after a cell swap
The M530 uses a fuel gauge IC that tracks charge state by counting coulombs against a stored discharge curve from the original cell. When you install a new cell, that stored curve no longer matches the new cell's actual behaviour. The IC reads voltage and interpolates percentage from the old map, so you get skewed numbers — often showing full charge when the cell is not, or dropping suddenly. One full discharge and charge cycle rewrites the reference curve and brings the percentage back in line.
Sudden shutdown at 20–30% on the replacement cell
This happens when the cell voltage drops below the modem or display load threshold faster than the fuel gauge expects. The gauge still reads 25%, but the actual cell terminal voltage collapses under peak current draw — the phone shuts off to protect the circuit. It is most common in the first few cycles before the coulomb counter is recalibrated. Run two full discharge-charge cycles without fast charging, then check whether shutdowns persist. If the voltage under load is still collapsing, verify the cell resting voltage sits at or above 3.6V before installation.