How Long to Charge a Samsung Galaxy S25 Ultra Battery?
Charging a Samsung Galaxy S25 Ultra Battery from empty to full takes about 2 h 19 min with its standard 45W charger. The battery holds roughly 73.8 Wh, and this page estimates the time for every common charger wattage, using the Lithium-ion (Li-ion / Li-Po) chemistry it actually uses.
Charge time calculator for Samsung Galaxy S25 Ultra Battery
Estimated charge time
2 h 19 min
Includes the slower li-ion taper phase above 80%.
Charge time by charger wattage
| Charger | Power | Full charge (0-100%) |
|---|---|---|
| Standard charger | 15W | 6 h 57 min |
| Fast charger | 45W | 2 h 19 min |
| Ultra-fast charger | 120W | 52 min |
Battery capacity: 73.8 Wh · Chemistry: li-ion
The Samsung Galaxy S25 Ultra's lithium-ion battery thrives when users adopt smart charging habits that balance convenience with longevity. Rather than waiting for your device to fully deplete, moderate top-ups throughout the day—especially after intensive sessions of gaming, streaming, or photography—help maintain optimal chemical stability within the cell. The device's rapid charging capability means you can restore substantial power in brief windows, making it practical to charge opportunistically at your desk, in your car, or while working, rather than relying on single marathon charging sessions that can stress the battery chemistry over time.
The wireless and reverse wireless charging features of the Galaxy S25 Ultra open new possibilities for seamless power management, though each charging method involves different thermal profiles that merit consideration. Wireless charging pads produce gentler, slower charging that generates less heat—beneficial for overnight or extended charging periods when heat dissipation is less critical. Conversely, the rapid wired charging option is ideal for quick top-ups when you need maximum speed, though keeping the device in a cool environment during this mode helps preserve cell longevity. Reverse wireless charging, a standout feature for charging accessories, represents a practical energy-sharing tool that works best in short bursts rather than as a primary charging method for secondary devices.
With the fastest charger listed here (Ultra-fast charger, 120W) it takes about 52 min. With the slowest (Standard charger, 15W) it takes about 6 h 57 min. The Galaxy S25 Ultra features a 6,000 mAh battery with 45W fast charging and support for wireless charging and reverse wireless charging.
Frequently asked questions
- How long does it take to charge a Samsung Galaxy S25 Ultra Battery?
- From 0% to 100% with the standard 45W charger, it takes about 2 h 19 min. Using a faster charger shortens that; using a weaker one extends it, see the table above for exact numbers.
- How should I store my Galaxy S25 Ultra if I won't be using it for several weeks?
- If you plan to set the device aside for an extended period, charge it to roughly the middle of its capacity range—not fully charged, not empty. Lithium-ion batteries experience slower degradation when stored at moderate charge levels rather than at extreme states of charge. Keep the device in a cool, dry location away from direct sunlight or heat sources, as elevated temperatures significantly accelerate chemical aging even when the phone isn't in use. Before returning to active use, a standard charge cycle will bring the battery back to full readiness.
- Does using reverse wireless charging to power other devices harm my Galaxy S25 Ultra's battery?
- Reverse wireless charging is a convenience feature designed for occasional use—topping up earbuds, smartwatches, or other accessories for short periods. Since the Galaxy S25 Ultra's battery powers the wireless transmission while also managing its own operations, using this feature during moderate battery levels is generally fine. However, frequent or prolonged reverse charging when your phone is already low on power can stress the lithium-ion cells by creating conflicting charge/discharge cycles. For best battery health, reserve reverse charging for times when your main device has adequate remaining power, and avoid relying on it as your primary way to charge secondary devices.
- How is this charge time calculated?
- We divide the energy needed (73.8 Wh times the percentage you're charging) by the charger's effective power, which is the charger's wattage times the battery chemistry's real-world charging efficiency (85% for Lithium-ion (Li-ion / Li-Po)). The same formula powers both this page and our API.
ChargeTimeCalculatorestimates are based on typical charger efficiency and battery chemistry, not a live connection to your device. Always follow your manufacturer's charging guidance.