Back in February, there was a Stack Social sponsored ad on Jalopnik for an 18,000mAH Power Vault for only $30 with free shipping. Seemed like a good deal so I bought it.
It took about a month to arrive... but since I'm in Canada and the vendor was in the US, I'm not surprised by this long shipping time. I bet they probably lost money on my order due to the shipping charges.
Anyway... the device looks as nice and feels as solid as you see in the pictures.
My daughter has used it quite a bit with her iPod Touch that she plays games on that kill the iPod's battery pretty quickly.
After running down the iPod completely, she plugged it into the 2.1A USB plug and continued to play for several hours... 5-6 hours I believe where her and a friend were taking turns using it for games, videos, etc.
After the Power Vault got below 50%, it abruptly shut off.
Then I recharged it and used it a few times. Most recently this morning, her iPod battery was drained, so she recharged it using the Power Vault. That knocked it down from 100% (all 4 lights on) to only 3 lights on... indicating 75% 'full'. Then I charged my iPhone which was at 85%... and that in turn caused it to go below 75%.
If this is truly 18,000mAH, it should be lasting for much longer.
Given that the iPod touch (which has a ~1000mAH battery) had an empty battery and my iPhone 4S (has a 1900mAH battery) that was 85% full... and recharging with the Power Vault knocked it down below 75%, I guestimate that this Power Vault at best has a 7000-8000mAH battery... not 18,000mAH as advertised.
But I'm going to do some further, more formalized testing. What I think I'll do is let my iPhone 4s get down to 50% and see how many times I can recharge it to 100% from 50% using the Power Vault. In theory, I should be able to recharge my iPhone from 50% almost 18 times.
We shall see...