Wouldn’t it be nice to be able to charge your device anywhere you go? Well, thanks to today’s modern technology, you can actually do just that. It’s called a power bank. Basically, a power bank is a mobile charger that you charge your device on the go — and all you need to do is charge your power bank in advance in order to do so. Once you’re all charged up and ready to go, you can slip your power bank into your bag and charge essentially any device including smartphones, tablets, and laptops. All of that charging goodness without needing a wall outlet! Talk about freedom!

Whether or not you currently own a powerbank, it’s important to know how many times you can charge your devices on a single charge. You might think that it’s straightforward, but it’s just a teeny bit more complicated than what you’d expect. More on that below.

Typically, if you want to figure out how many times your power bank will charge your device, you’re going to have to use some math. To do this, the easiest way is to divide the mAh of your power bank by the mAh that your device’s battery is rated at. An example of how this would look is the following:

mAh of power bank / mAh of device battery = a number of times your power bank can charge your phone

By this logic, if you have a 5000mAh power bank and you’d want to to fully charge an iPhone 6, you’ll be able to do so 2.7 times. The iPhone’s battery capacity is 1810 mAh, thus, as you can see, this is what the equation looks like (5000/1810 = 2.7).

You should know, though that these calculations are never 100% accurate, so please take into consideration the fact that your power bank will naturally degrade over time.

Can You Use the Power Bank While Using Your Device?

Of course you can. People usually end up using their power bank when they need their device functioning. Thus, you’ll see many people with their device’s attached to their power bank while they’re online, taking a call or watching a movie. However, there is a difference between a device that’s plugged into a power bank without being used and a power bank that’s used to charge a device that’s currently being used. In all honesty, the difference is huge.

If you’re using your device while it’s being plugged into a power bank, though it’ll charge your device, it’ll also drain more power from it. This is why if you’ve done this before, you probably noticed that your device wasn’t really charged at all. This is simply because it’s using the power faster than it would if your device wasn’t being used.

Whereas, if you leave your device alone or in airplane mode while it’s being charged with your power bank, you’ll be able to receive a full charge since your device isn’t using up much battery power.

Will the Power Bank Always Be Able to Give Me a Full Charge

Here’s the thing about the power bank. The more charging cycles your power bank undergoes, the more degradation said battery will experience. Ideally, what will happen is that after approx. 300 charging cycles, your power banks capacity will reduce to 80%.  For example, if you’re using a 5000mAh power bank, it’ll be reduced to 4000mAh capacity. Though, this also varies depending on the temperature of the power bank.

Now, if you’re experiencing that your power bank isn’t working properly, it could be for a couple reasons. If your power bank appears to be completely dead and non-functioning, it could very well be that your power bank is completely drained. You’ll be able to tell this when you plug it into a power source and a light blinks. If this is the case, it simply needs to be charged.

Another factor could be that it went into sleep mode. Your power bank will completely cut-off power and go into sleep mode when it detects an over/under charge. This could be due to a faulty cable, so please check it to make sure there’s no damage. To solve this, simply plug it into a power source.

Now that you know everything about your power bank and how it’ll be able to charge your device over time, you’ll be able to make proper calculations in order to tell the amount of charges you can reasonably expect to get out of your power bank. Happy charging!