Hold a good charge and easy to travel with
929715
Bought two, they are well worth the money. Hold a good charge and easy to travel with. Excellent for the price.
2331068
My dad uses these and said they last nicely and hold a charge well.
520130
This has come with me through trips to India, Japan, Singapore and hundreds of day and weekend trips camping or traipsing through urban environments where I can't necessarily have power.  I have a newer iPhone and its battery is good, but not 8 hours of constant data use and photo/video taking good--I keep it plugged in to this battery and I can easily outlast the day (or two).

The charging ports do sometimes shut off after some time (20-30min?) so you have to hit the "on" button every once in a while to be sure you're charging, but it's a minor issue and I appreciate that it attempts to save itself from devices that get more power hungry when they think they're on AC.

It's about the size of my phone and it slips easily into my back pocket.

It holds its charge for months without being cheapest--I left it for 3 months in a drawer and it was able to charge my phone from near dead twice before I was able to find a plug for it.
255684
Decent alternative to carrying around a secondary internal battery since many devices have internal batteries that are not easily or quickly accessible anymore. Good for on-the-go charging and battery life extending.  It seems to do well keeping its charge when not used for several days. A color coded LED indicator activated by a button on the pack itself indicates the current charge level (Green = charged, Blue = medium charge, Red = low charge/needs charged). My wife will have it when she goes on an MOR cruise later this year.  I'm sure it will serve her well.
1415943
This charger/battery combo is a lifesaver for travelers that don't see electricity all that much. I travel by bicycle and use my phone as a GPS, and many times when camping there is no way to charge my phone. With some extra batteries like these, problem solved! I have used these batteries like crazy and they hold a charge just as well as the stock OEM battery that came in my Samsung Focus. They are still charging and working just fine over 2 years later! I'm here to order another identical set because I finally left my charger in the wall of some random cafe on the road :) Note that the charger is not the most sturdy of devices, so it won't stand up to much abuse, but the price is great for what you get.
449418
I use my iPhone on long trips for music, videos, games and the charge won't last coast to coast.  This external battery let's me recharge (multiple times) and use the iPhone simultaneously. Yes, it is too big to fit comfortably in a pocket (per the complaints below) but it fits comfortably in my backpack and the unique orange color makes it easy to find; it holds a charge for a very long time, and is intuitive and easy to use.  I recommend the Jackery Giant for anyone with a similar need for a convenient iPhone power source.
4234651
Not only is this a good deal, but these work so much nicer than the corded and gas ones I have used.  These are light, therefore easy to manage.  The charges last all day if I use one of them non-stop for hours in a day, like 4 to 6 hours on one full charge.
3962185
I've been using this a few months now including two transcontinental flights.  It carries a really good amount of charge (over 2 full charges on my iPhone 5s) for the size and weight.  Easily fits in my purse.  The indicator lights are a nice feature.  Charges fast and I've used the phone while charging.  It's been great to take while traveling.  Really saves me peace of mind knowing my phone won't run out.
3070939
If you find yourself on the road a lot, away from reliable sources of power, a backup battery like this might be nice to have. It features a couple of USB ports that you can plug mobile devices into for an extra bit of power. It works just fine, recharges in just a few hours, and keeps your devices going when you're on the run. I have no complaints about it.
3784764
These are great to have around.  You can be charging and its easy with the extra length to be using the device at the same time.
1902972
This battery can charge my Nexus 7 and my iPod Touch 2-3 times each before needing a recharge.  Despite its massive battery capacity, it is still light enough and small enough to carry without difficulty.  The included carrying bag is a nice touch, and the unit itself feels pretty durable.

One thing I would like is a better status light.  The color-change based on the battery charge level is nice, but it is very difficult to tell whether the device is on or off based on the status light - and the "On", "Off", and "Check Charge Level" functions are on that single button.
2406751
I really like this charger, I bought it to travel with and it's small enough to go through TSA in my carryon bag. It did a good job charging my phone and my tablet and it holds a charge for a long time.
548373
So far I'm very pleased with these. We use these for things around the house that would normally accumulate a lot of trash batteries and I have no complaints about their holding a charge. Will update if this changes.
978236
Holds a decent amount of charge. Not easy to carry around though
516550
Easily charges my iPhone once and slips into any bag or suitcase. It loses battery even if you don't use it, so I would recommend charging it every night if you're traveling. A larger battery with greater storage would be better, but the convenience of having this small battery in my purse instead of using a backpack is worth it.
3908532
Work really well and charge quickly. The pouch they came with is small and the cord is appropriately sized for travel
4662960
These are wonderful to have. They are easy to keep convenient or on the go. Put a few in the glove compartment. The cord stretches out easily and then give it a tug to retract back in. The ends fit into your electronics well. I tested it with the galaxy note 2. My son thought they were cool. I purchased this item at a discount for my honest unbiased review.&nbsp;<a data-hook="product-link-linked" class="a-link-normal" href="/Micro-USB-Cable-Retractable-Cable-MaxMall-2-Pack-High-Speed-2-5-FT-USB-2-0-A-Male-to-Micro-B-Data-Sync-amp-Charge-Cable-for-Android-Samsung-Galaxy-HTC-LG-and-More-Blue/dp/B017149EF4/ref=cm_cr_arp_d_rvw_txt?ie=UTF8">Micro USB Cable, Retractable Cable, MaxMall 2 Pack High Speed [2.5 FT] USB 2.0 A Male to Micro B Data Sync & Charge Cable for Android, Samsung Galaxy, HTC, LG and More, (Blue)</a>