1. First, you need to check out your device's operating power (measured by watts). If it is less than the output power of your Explorer's AC port, it can be supported by the Explorer. For example, the Jackery power station Explorer 500 can run AC devices at 110V that require less than 500W. 2. Then, you can calculate the charging time with the following formula: Working time = Explorer's Watt-Hours * 0.85 / operating power of your device. Example: Let's assume your device's power consumption is 60W (might be a box fan), and you want to use the Explorer 500 to run your device. 500Wh*0.85/60w = Roughly 7 hours of working time Please note the actual power consumption varies based on many factors. If you have any more questions, please reach out to us via hello@Jackery.com or Amazon. We will get back to you within 24 hours on business days, and we'll be more than happy to help.