2500mAh Power Bank Mini,Back-up Phone Battery Pack Ultra Slim,Pocket Size Thin External Phone Battery Pack Emergency Phone Power Built-in Charging Cable for Android Micro USB and Apple

I purchased this specifically to keep in my purse so I can charge my Kindle Paperwhite on the go and it works great. It's small - maybe 1/4 inch thick and the size of a credit card (I've attached a picture of it with my Paperwhite for scale) - so it fits perfectly in my purse and doesn't take up much room. I absolutely love that it comes with the cord already attached so I don't have to drag around an extra cord and the length is just enough (about three inches) so I can charge my Kindle and hold the charger behind the Kindle while continuing to read. The cover of the charger has a leather-like feel so it doesn't slip around when I'm holding it which is also nice.Charging the unit is fast and easy and using it is just a matter of gently pulling out the little cord and plugging it into the item. There is also a tiny iPhone adapter inside, which you sort of stick the end of the regular charger into until it clicks and then you can pull it out to use it. From a full charge I've found that I can charge my Paperwhite fully twice, or my iPhone once, which I was pretty impressed with considering the small size of the unit. When it's providing power the light lights up blue on it so you know it's working.As for durability, I use this about once a week and I've had it for about two months now and it's working fine. The cord is still secure and it charges and provides power nicely.Overall, this is a great size and has good power and I definitely recommend it.

Compact, sturdy case with enough amperage to charge my old iPod Nano 2 or 3 times. The aging battery in my iPod doesn't run as long as it used to, so this Power Bank rides in my pocket behind the iPod and provides long listening time. I like the short cable (2.25 in. or 60 mm) permanently wired to the Power Bank so there's no excess wiring. The cable comes with a Micro USB plug, but an Apple lightning adaptor is included and snaps on over the Micro USB plug. Stowing the cable with the lightning adaptor attached is not as neat as with only the standard plug, but works okay.It's possible charging or running the iPod directly from this Power Bank may not be the best treatment for the iPod battery. The charge rate from the Power Bank is much faster than with a proper smart wall charger that regulates the rate to avoid damaging the iPod battery. Oh well, this solution is way cheaper than replacing the battery in my iPod.

Slim and vercitile. Gets hot in pocket though.

I've been independently testing lithium ion batteries and battery products for a while now - no one is paying me to do this, I just like understanding how the products actually work and what it is that I'm buying.What I have found during my testing is that all the manufacturers of lithium-ion products artificially inflate their mAh numbers. They're not outright lying, exactly, but they test under wildly unrealistic conditions that are simply not possible in any real-world application.You see, lithium-ion batteries discharge less total power the faster they're discharged. So what the manufacturers do is test their products at a tiny little trickle discharge of around 75 milliamps or so. That gives great high numbers for total capacity that are technically true, but it is simply not possible for most consumer devices to operate at a current that low. As an example, my phone draws 1250 milliamps when charging with a regular, non-quick charge cable and charger. So I have found the actual real-life capacity of a battery or device is about half of whatever mAh capacity they're claiming. I've tested multiple batteries and power banks from manufacturers all over the world and they all do this. If you get half the capacity they're claiming, you're actually doing fine.I normally test at a load representative of what I think the minimum real-world power draw would be at the slowest possible rate of charge for a typical consumer device - 750 milliamps. That's almost half of what my phone actually draws when charging, and much lower than this and it won't charge at all. However, this little thing is only capable of putting out 1.4 amps (1420 milliamps) at an absolute maximum, so I had to test it at a gentler 350 milliamps.So with all that said, this micro power bank has a stated capacity of just 2500 mAh. What I got out of it at 350 milliamps was 1720 mAh, which is a bit above average. It's usefulness is also sharply limited by it's lack of USB-A, USB-C, or Lightning output connectors, and it has no state-of-charge indicator at all, not even the typical small row of LEDs. All you get is a LED that blinks when it's charging. These facts combined with the small capacity makes me think this isn't intended to charge a phone at all. I don't know what it's intended for, honestly.So in summary, better than average capacity for it's size but lower than average maximum output, a complete lack of any useful output connectors, and no state-of-charge indicator. At least it's quite small, just a little larger than a credit card, but at this point why not just make it actually credit-card sized? I have no idea. I guess the integrated micro-USB connector is kinda nice?

This is so far my most favorite power bank. It is a tad bit bigger than a credit card and slimmer than a regular iphone. I would say that this is by far the smallest and slimmest power bank that charges my phone not only as fast as a plugin charger (in two hours my phone went from 17% to 100%) but also silently and without any kind of connection issues. It comes with male micro USB plug but comes with a mini lightning adapter that is kept safe under the attached charging cable so that it does not fall out when the charging cable is securely in its place. At first I had trouble putting the cable back into its place but all I really needed to do was to just gently press it against the slot and then push it in. It does emit blue charging light as it is working, so it may be annoying for some. I really really like this product.

The size is great and the idea would be great if it worked.It comes a little charged so i was excited when I got it but after testing it for a few days It’s disappointing. I gave it a good charge and when I went to use it at work it got really hot at the top but I figured It came from being in my pocket. So I left it on the desk and still when I went to pick it up it was extremely hot to the touch. Also it doesn’t charge my phone but maybe 30% before it dies. FORGET about using the phone while it charges(iPhone Xr). The built in piece is nice but I put it back in backwards once and it was a bitch to get out.