About this replacement
Kyocera Hydro Edge / C5215 — 3.7V Li-ion Replacement Battery (SCP-54LBPS)
This is a 3.7V, 1300mAh Li-ion cell replacing the OEM SCP-54LBPS battery in the Kyocera Hydro Edge and C5215 smartphones. It matches the original form factor and connects directly to the device's charge IC and fuel gauge circuit. Install it when the original cell no longer holds a useful charge across a normal day.
- Hydro Edge and C5215 compatibility: Both models run the same 3.7V single-cell architecture with an identical connector and BMS handshake protocol. One cell fits both.
- Bench tested on actual hardware: We cycled this cell through charge and discharge on a Hydro Edge unit. The BMS accepted the cell without error flags, and the charge IC completed a full constant-current to constant-voltage transition at 4.2V as expected.
- Fuel gauge recalibration on first use: After installing this cell, run one complete discharge to around 5% before charging to 100%. This gives the Kyocera fuel gauge IC a full sweep of the new cell's discharge curve. Skipping this step causes the OS to report percentages calibrated to the old degraded cell.
Why the Hydro Edge reports wrong battery percentage after a cell swap
The Hydro Edge uses a coulomb-counter fuel gauge IC that learns the cell's capacity over charge cycles. When you swap in a new cell, the IC still holds the old cell's learned parameters — so the percentage readout is mapped to a degraded capacity baseline, not 1300mAh. The phone may show 50% when the cell is actually near full, or drop from 30% to 0% without warning. One full discharge-to-charge cycle forces the IC to relearn against the new cell curve and corrects the readout.
Sudden shutdown at 20–30% on the replacement cell
This happens when the modem or display pulls a current spike that drops the cell voltage below the BMS cutoff threshold — typically around 3.0V — even though the gauge still shows charge remaining. A new cell that hasn't been calibrated to the fuel gauge IC is most vulnerable to this on the first few cycles. Run the recalibration cycle first: discharge to 5%, charge uninterrupted to 100%, then repeat once more. After two full cycles, the fuel gauge tracks the actual voltage floor accurately and the shutdowns stop.