About this replacement
Samsung Galaxy K / S4 Zoom — 3.8V Li-ion Replacement Battery (B740AE)
This is a 3.8V, 2300mAh (8.74Wh) Li-ion cell built to fit the Samsung Galaxy K and Galaxy S4 Zoom camera lineup. It replaces OEM part numbers B740AE, B740AC, and EB-K740AEWEG. The cell fits the same contact footprint and connector orientation as the original.
- Galaxy K and S4 Zoom platform fit: These models share the same battery bay geometry, contact layout, and BMS communication protocol — a single cell design covers the full range listed in the compatibility table above.
- Bench tested on actual hardware: We ran this cell through full charge and discharge cycles on Galaxy S4 Zoom bodies. The BMS accepted the cell without error flags, and voltage held stable across both still shooting and short video bursts.
- First-install charge cycle: On first use, run one full charge cycle through the camera body or OEM charger before heavy shooting. The Galaxy K BMS uses that cycle to map its battery-remaining display to the new cell's discharge curve — skipping it causes erratic percentage readings.
Flash recycling slowing down before the battery indicator drops
The S4 Zoom's capacitor recharges between flash shots by drawing a short burst of high current from the cell. As cell voltage sags under repeated flash use, that recharge current drops, and the recycling gap between shots gets longer. This happens even when the battery percentage display still reads mid-range, because the indicator tracks average voltage, not peak-draw headroom. If recycle time stretches noticeably, the cell is near the end of its usable charge — swap or recharge before a critical shoot.
Battery percentage jumping between readings mid-shoot
This is a discharge-curve mismatch between the new cell and the camera's fuel-gauge thresholds. Samsung's BMS maps battery percentage to fixed voltage steps calibrated on the original cell — a replacement cell with a slightly different discharge curve hits those voltage thresholds at different points. The fix is completing two to three full charge-discharge cycles in the camera body. After cycling, the BMS recalibrates its reference points and the percentage display stabilises.