iPhone back-up batteries

[jeepinbanditrider]

Run a Cig lighter plug from battery and just charge phone from car charger.

This is essentially what I run on the bike but when on foot such as hiking it's not really an option.  backup batteries can help get me an extra day out of the phone if needed.  Turning off non-essential stuff on the phone like bluetooth, wi-fi, ect really helps extend battery life too.  The biggest one is turning off the "radio" portion of the phone that actually recieves and xmits to the cell towers.  Turn that off and your smart phone will last a long while.  Even while playing music.

[reppans]

I have the GZ guide 10 plus Adv kit.

It works as advertised in perfect sun (no clouds, perpendicular to sun) and will charge the G10 4xNiMh batts in about 3.5 hrs.  The 4 NiMh batts are probably good for 2 charges to an iPhone (I can just about fully charge my iPhone with 2 NiMh from my iGo, mentioned above).  The NiMh G10, or Nomad 7, putting 1 amp will charge a iPad, albeit slower than the 2 amp wallwart.  The new iPad3 has a 42 w/hr batt, the iPad2 has a 25 w/hr batt and the G10 with 4 NiMh batts has around 9 w/hr.  Accounting for conversion losses, the best the G10 could proabably manage is a 20-25% charge to the iPad2 and a 10-15% charge to the iPad3, the latter of which I have tested.

Cannot compete with charging from a bike battery, and it's kinda big/heavy for emergency use only.  

I also have a Powerfilm 4xAA charger (6panel, non USB version) that packs about 1/3 the size/weight of the GZ kit.  It's about half as efficient as the GZ (2 batts in 3.5hrs or 4 batts in 7hrs), but it wins the power to size/weight analysis and is a better carry for emergency use only (once again, with the iGo to charge my iPhone from the NiMh).

[cyjo]

Not as convenient as a case, but I have this product, mine actually is the model before this:

http://www.amazon.com/Incredicharge-I-5000-External-Capacity-Blackberry/dp/B006YJBITS/ref=sr_1_23?ie=UTF8&qid=1338343400&sr=8-23

It would require you to plug your cable into it to charge but it's got enough to capacity to charge my android phone 2 or 3 times although slower than a wall charger obviously. Mine came with a cable to plug into an AC charger I already own and it has a standard usb port to charge different products.