About this replacement
Apple iPhone 5C — 3.8V Li-Polymer Replacement Battery (616-0667)
This 3.8V, 1500mAh Li-Polymer cell replaces the original battery in the Apple iPhone 5C, including A1526 and A1532 variants. It also fits the iPhone Light 32GB. Voltage and connector match OEM spec — no modifications needed for installation.
- iPhone 5C / A1526 / A1532 compatibility: These models share the same 3.8V battery architecture, ZIF flex connector pinout, and BMS handshake protocol. Any cell in this group draws from the same charge IC, so one replacement part covers the full range.
- Bench tested on actual hardware: We ran this cell through the iPhone 5C charge IC and confirmed the BMS negotiated correctly at 4.2V cutoff. The protection circuit tripped cleanly at the low-voltage floor without requiring a manual reset.
- Fuel gauge recalibration after swap: After installation, run one complete discharge down to auto-shutdown, then charge to 100% uninterrupted. This lets the coulomb counter recalibrate against the new cell's discharge curve — skip it and the percentage readout will drift from the first day.
Why the iPhone 5C reports wrong battery percentage after a cell swap
The iPhone 5C stores a learned discharge curve for the old cell inside the fuel gauge IC. When a new cell goes in, that stored curve no longer matches the actual voltage-to-capacity relationship of the replacement. The IC keeps reading against the old map, so reported percentage drifts — often showing 30% when the phone is close to shutdown. One full discharge-to-shutdown followed by a complete charge cycle forces the IC to relearn the curve and restores accurate reporting.
Sudden shutdown at 20–25% on the replacement cell
This happens when the modem or display triggers a current spike that drops cell voltage below the BMS protection threshold — even though the fuel gauge still shows charge remaining. The 5C's power management IC does not compensate for the higher internal resistance of a new uncalibrated cell under load. The phone interprets the voltage dip as a dead cell and cuts power. Running that first full calibration cycle brings reported percentage in line with actual cell state, and the shutdowns stop.