When planning a trip, you want to make sure you have enough power for all your electronic devices. Whether you're going on a long trek or taking a city break, it's important to know how many watt-hours (Wh) of capacity you'll need to keep everything charged.

Follow these steps to accurately calculate your energy needs:

1. Make a list of your devices:
Start by writing down all the devices you plan to take with you, such as your smartphone, laptop, camera, and tablet.

2. Determine energy consumption:
Find the energy consumption (in watt-hours, Wh) of each device. You can usually find this on the label or in the device's manual. If you only have the consumption in watts (W), you can calculate the Wh by multiplying the power by the usage time.

3. Calculate the total energy consumption per day:
For each appliance, multiply the energy consumption (in Wh) by the number of hours you use it daily. Add up the Wh values of all devices to calculate your total daily energy consumption.

4. Determine the duration:
Multiply your daily energy consumption by the number of days of travel to calculate your total energy requirement for the entire trip.

5. Add a margin of safety:
It's smart to add an extra 20-30% margin for unforeseen circumstances or extra usage. This will ensure that you don't run out of power.

6. Choose an appropriate power bank or power station:
Make sure the capacity of your power bank or power station is sufficient to cover your calculated energy needs. For example, if you have a total energy requirement of 200 Wh, choose a power bank or power station with a capacity of at least 250 Wh. This will not only give you enough power to charge all your devices, but also an extra reserve for unexpected situations.