I'm afraid I don't think it's do-able on your budget.
My iPhone uses 1.5ah to charge and the iPad 7ah, so that's 8.5ah to charge just those two. If you have multiples over multiple days then you'll see you need a pretty big battery to cope!
I have seen these units recommended on here, and you could get two for your budget but even then would still only have 20ah of power to play with.
Have you seen the power pack I recently made to charge my appliances whilst camping? This would be outside your price range at around £140 but could be used for so much more than just charging a couple of phones - water pump, lighting etc etc. You could even add a solar panel for £25 and it would keep the battery charged :)
Check out the Anker range of portable batteries. I am going to a festival and buying the Astro E5 which is £38 - it will charge my phone around 8 times on one charge of the battery
I sell portable chargers for £15 with postage included in the price . All legit through PayPal for seller and buyer protection. Brilliant charger :) email me if interested.
i23rhian at aol.com
This is Romoss Portable external battery pack Charger Power bank, It compatible with almost All smart phones and other device with USB port, this is THE ultimate POWER SOURCE!
It Compatible with Most Cell Phones:
- Apple iPhone 5/ 4S / 4 / 3GS/ ipod touch/nano/ iPad/iPad 2 the new iPad
- HTC One X S/Sensation XE XL / Wildfire S / Desire HD / Desire S / Incredible S...
- Samsung Galaxy S 2 / S / Note / Nexus / Ace / Star ...
- Blackberry Bold 9900 / 9700 / Curve 9300 / 8520...
- Motorola Atrix 4G / Photon 4G / Defy / Flipout / Milestone 2 ...
- Nokia Lumia 900/800/600/710/ N8 / C6 ...
- LG Optimus 3d / 2x / one ...
- Google Nexus One / Nexus S ..
- Sony Ericsson Xperia / X10 / Arc / X10 Mini Pro...
- Amazon Kindle, Kindle Touch, Kindle Fire...
- Others Nook Color, NDS, MP4, MP3, Portable Wifi, PSP (NOT with PSP vista)
Light and Small:
- Dimensions: L138*W62*H21.5mm
- Weight: 445g/15.7ozs
- it is very convenience to take it out
High Capacity - Long Lasting:
- Capacity: 10400mAh
- Type: Lithium ion (Li-Ion)
- Input Charging Time ~12 hrs
- Life Cycle > 500 Times
- Input: DC5V 3A MAX Max
- Output: USB1:DC5V 1A USB2:DC5V 2.1A
Battery Life Extension on Apple products:
Box Contents:
- 1x 10400mAh Romoss Battery Pack
- 1x Romoss Micro USB charging/data cable
- 1x User Manual
We have just bought one for £15 at Wilko's. Its small (about the size of a small tablet and works fine).
Be sure to leave it in the sun or under a lamp until it's fully charged though, usually takes about 48 hours to charge initially, otherwise it wont work to its full potential.
------------- July - Dalby Forest
August - Pembrokeshire
Hi Wendy - Just an update on how I've got on so far. My charger arrived on Tuesday. It was already charged up on arrival, and so far it has fully charged my Galaxy S3 four times and still has juice left in it. It looks like it will certainly do the job for me. Keep us posted on what you go for and how you get on. :D
p.s. It charges the phone up as quickly as a usual plugged in to electric charge would.