Instruction: Answer the given question using the supporting document.

Input:
Question: How do you charge the charger?  Can you plug it into the wall?
Document: This little device is at least one full battery charge in a little package no larger or heavier than a pack of gum. if you're running low on power you simply plug your phone into the USB jack and it will charge your phone just as fast as if you were plugged into a wall socket. You can also talk on the phone while it's charging.In the two weeks I've owned the the Jackery Portable Charger, it's already paid for itself several times over in sustained productivity.
I specifically chose this portable charger for those times when I am in the midst of a great read and my iPad is losing the last bit of its juice. I was so looking forward to being able to plug it in to the mini Jackery and just keep on reading...the first time I used it I noticed it was very slow charging, and was a little concerned, but continued reading anyway. Now my iPad will not hold a charge, not even when fully charged on its normal wall charger.
The proprietary end fits the Jackery and other is USB. I attach my Apple USB Power Adapter and plug it into the wall socket (or you can just plug it straight into your laptop to charge). Also, I still don't know how long the Jackery will store a full charge. I guess that's TBD.
I recharged the battery with a wall plug and it charged in just a couple of hours to 4 lights/full level. Very useful and high quality product!
I really love this extra charger. It has saved my day several times already. My students  love it too the charge is faster than plugging in to a wall socket.. Will make a great Graduation gift for you favorite graduate or a thoughtful gift for Dad.
The button and light indicators all worked and the thing even held a charge. The device can completely charge my 2300mah battery without issue and takes as long as a standard wall charger.After using the mini for a while you get to know how it works and when it does work it can charge your phone and save it from the brink of death. I'm glad i've had this while stuck in the car or anyplace without access to an outlet.TL;DRWorks, but is confusing.
First time the JM worked, fully charging my iPhone (don't recall if I started from 0%). The second time, it partially charged my iPad 1 before depleting its capacity. I then took it on vacation, and it would not transfer any charge although fully charged itself. My iPhone did not detect it, and I couldn't blame the cable I used. Luckily I brought my regular wall charger. I returned the JM to Amazon.My purchase is but one data point.
I received this as a gift recently and LOVE it! Very convenient to carry in a purse and provides a reliable charge to my phone...before, I had to carry around my charger and search for a plug whenever I was out! Highly recommend this product.
If you've ever gotten frustrated because your iPhone died and you had no place to plug your charger, this is for you. It's like having an outlet in your purse! The only downside is you have to remember to bring the charger cable with you, and you have to charge the battery pack with a different cable. Even so, I love it!
I had this charger (which is more costly than other similar chargers) and it worked for the first couple of charges with my phone and then stopped working. I would plug it into my phone and...nothing...no charge. Sent it back ordered another one and had the same issue. Gave up for a while and then on a whim, ordered a THIRD unit, thinking that maybe it was just a bad batch.
Answer: The end that charges the item has to be plugged into a USB receiver.  Either a PC or an iPhone plug that plugs into the wall. To add to my last review... I must say that after re-charging it and using it a few times, it seems to be holding a charge way longer then the first time, making it more handy to have for emergencies!  I'm considering purchasing another for my teenager.  Hope this helps!