Some great reviews above. Good luck to all 
Here a cut from my review for the Anker PowerCore 5000. It was over 600 words but to play by the rules I’ve had to shave bits off from various corners (and the cycles performed). But I’ve been able to bring it down to 295 words (according to MS Word)…
With the amount of USB gadgets we own, it is always handy to pack a powerbank in your bag for those awkward moments when your device runs out of juice at the most crucial time. I’ve purchased a few of them; from the small Anker Astro E1 5200 mAh powerbank to more expensive powerbanks that house up to 25,000 mAh. So what makes this one any different?
Well first of all the size. It measures 12.5 x 6.3 x 1 cm. That’s pretty slim by the way. I have compared the thickness of the PowerCore 5000 and Astro E1. Please take a look at the images provided.
The PowerCore 5000 came more than 2/3 charged. There is a 3-step power indicator; 3 lights = 100% or less, 2 = 66% or less and 1 = 33% or less. It looks and feels premium. Holding both your phone and the powerbank in one hand is erm, pretty handy. Reminds me of the power cases that are available for iPhones.
I connected various micro USB cables to see the maximum Amps I can get to charge a Samsung Galaxy S5. Whilst the Samsung cable could only manage 1.46 amps on average, my most powerful USB cable (by RavPower) managed 1.92 amps at 5.10v. That’s remarkable and almost the maximum of 2 amps this can pump out. I then tried the ‘little’ Anker cable that came with the PowerCore and…wait for it…it matched the 1.92 amps! The little man means serious business! In fact it matched the maximum all my devices accept.
Recharging the PowerCore was a breeze with the included cable, again recharging at 1.95 amps.
In conclusion, Anker has developed another masterpiece. Unique in design, the PowerCore 5000 is certainly a contender for my go-to powerbank.