PowerGen Mobile Juice Pack (External Battery Charger)?

I have an iPhone 4s, and the battery life sucks. But, alas, I'm stuck with it.

I'm going on a trip in a couple of months, and I've been searching for an external battery charger for on-the-go travel.

I've been looking at the PowerGen Mobile Juice Pack (http://www.amazon.com/PowerGen-External-Blackberry-Sensation-Thunderbolt/dp/B005VBNYDS/

Did any of you ever use one? Was it good/bad/other?

Also, since it doesn't seem to come with an AC adapter, what did you use to charge it? Can you just use the Apple AC Adapter? You can use your laptop to charge it, but since I'm not bringing my laptop, and I'll be using this for multiple devices (2 iPhones, sister's Nexus 7,) for multiple days, I can't obviously use it without an AC adapter to recharge the PowerGen.

Anyways, I'm just looking into it.

Just got an iphone 4s, what case should i buy

I'm a guy and i know there are lots of types and colors, but i don't know what kind to get. Like the otterbox? But i heard that was really bulky. Any ideas on a slim cover but still good protection?

Anyway to recover iPhone 4 history?

So guys and girls I recently got a used iPhone 4 and I'm curious, is there any way to recover the internet history? I'm curious to see what the previous owner has been on.

Is it possible to rejailbreak a jailbroken iphone 4s already?

Last night i downloaded something from cydia and it crashed my phone now its stuck at the boot logo and when you turn it on it still has the same thing. Can someone help me i tried recovery mode and dfu but i don't want to lose any of my data.

Iphone 3gs battery dying quickly?

After installing cythia on my iphone 3gs the battery is being drain out even when I don't use the iphone + if battery dies out, it brings iphone to the apple loggo and I have to go to the whole process of setting it up again, the reboot on the computer. It's a hassle. How can I fix that?

Voicemail quit working on AT&T iPhone 4?

This has been going on since December. My visual voicemail was working perfectly fine, no problems, nothing. Until one day around March my friend asked me why if I got her voicemail, I was like no.sorry. Then I looked in my voicemail and the last voicemail I got was in December. I thought that was really weird so then I called my cell phone off of my house phone and left a voicemail. Didn't get it. I even dialed 1 on the keypad and went to my voicemail and it said "You have zero messages" Okay that was weird, but I don't really listen to voicemails so I didn't mind. Around May I had to reset my phone for a different reason, but my voicemail didn't fix. In June I jail broke my phone so I don't think I can bring it to AT&T or anything… I'm now waiting for a phone call that I really need and if I miss it I'm afraid they will leave me a voicemail and I will never get it. Any ideas on how to fix this problem?