I recently got a Kmashi 15000mAh battery pack and I have been loving it. 15 Ah is a lot of juice for all devices I have, and I can always count on this to have some juice left. It is not just the numbers that amazed me, but I have used it for days without my charger with me. I can charge my OnePlus one and Galaxy Note 8 twice, and still have juice left to charge my iPhone and S6. This is an amazing product for people who travel a lot.
Capacity - 15000mAh or 55.5Wh
Input - 5V/2A
Output 1 - 1amp 5V
Output 2 - 2amp 5V
Size - 81*156*21mm
Weight - ~450g
Real world performance
I have used this battery pack with two phones. I took screenshots of the battery input received from this battery pack. The first image is for OnePlus One and the other is for Galaxy S6. The battery pack doesn't support quick charge 2.0 and the maximum output is not as high as I expected it to be. The input rate measured was lower than the listed output on the battery specs section, but it definitely charged the devices pretty quickly; so, I am not complaining.
I have always wanted a battery pack that wouldn't die on me when I need it the most. I have had a 5000mAh and even a 10000mAh battery packs before this and they would die on me after two devices max. If I have to remember to charge my battery packs too, then I know for sure it is not working for me. I got this 15000 mAh battery pack from Kmashi in hopes of getting a battery pack that I can throw in my bag and forget about it. The battery in this is huge, and there is minimal loss of battery when the battery is not being used; therefore, this battery pack will keep on going with you. I have travelled with this device and my OnePlus One without my charger for 3 days, and I never missed my charger.
For all the travel lovers, keep in mind it is not a small or thin device. It is almost 3 times thicker than an iPhone 6. It is a heavy product, which you might not wanna carry in your pocket. It has 2 USB ports, but that has a catch. When you use both the USB ports together, the battery outputs a total of 2 amps, which means 1amp from each port.
In order to charge this battery pack, I used a 2.1 amp USB wall adaptor (not included in the box). The battery pack takes almost one night to charge from zero to full. It is not easy to sleep with this charging beside your bed, as it's blinking LEDs are very bright. They can brighten up a room more than any night lights you have seen. Putting an electric black tape on them while the device is being charged is a good solution.
Large capacity battery
Feel and finish is all plastic but doesn't creek
2 USB Port to charge
LEDs are very very bright
Long charging time
No Quickcharge 2.0 support