Hi Pete and Pete!
Since I don't have an iPad and the Joos Orange's output is insufficient to charge my netbook, I have so far used it only to charge the following:
• Eneloop and Eneloop XX AA/AAA batteries in an Eneloop USB charger (to power my GPS, LED headlight, LED bike blinky taillight, MP3 player, and AM/FM/Weather radio).
• Camera batteries (GoPro HD Hero2, Panasonic TZ-5, Sony DMC-HX20, and the embedded battery in my Flip Mineo HD vidcam).
• Embedded battery in my Panasonic electric shaver.
• My "dumb phone" battery.
• And to top off partially depleted batteries among my spares (I usually pack 1-2 pre-charged spare batteries for each of my most heavily used or most critical gadgets).
For these purposes it has worked as well as a USB 2.0 outlet on my computer, a USB mains adapter, or my Tout Terrain The Plug2+ when riding. The goal was to have a backup or secondary means for charging on days when I might not make much distance or for layovers when the dynohub is not running. I have found the Joos Orange worked well to charge each of these batteries/devices from flat in a time comparable to mains power. I found the most efficient charging scheme was to charge the accumulator battery from the sun during the say and only charge or top-off my gadgets at night, in the dark. This allowed the Joos Orange's accumulator battery to have the entire next day to charge, either from flat or to top-off any remaining charge. Trying to charge gadgets during the day (as the panel itself was replenishing its own accumulator battery) made for diminishing returns. I make sure I leave home with a fully charged Joos so I have a ready reserve of power. This is a good strategy with any sort of accumulator battery. I also pre-charge my Eneloops before leaving home so they're ready to go. I top off the batteries for my most-used gadgets or those with highest draw/drain daily (i.e. my Garmin Oregon 400T, which runs about 17 hours while continuously tracking). Less-used or less power-hungry items can slide for awhile (my LED headlamp has a 65 hour battery life, my radio between 31-54hrs. Of course, I produce dynopower for charging while underway during the day, so depending on demand, the Joos does't always have to do much charging at night while in camp.
As for how long it takes to charge the Joos Orange's internal accumulator battery, the company's support page (
http://solarjoos.com/support ) says...
It depends on your location, time of year, time of day, temperature, sunshine/cloud level, the angle of the sun in relation to the solar cell and whether you move the JOOS Orange to follow the sun or just let it sit still. The quickest would be about 10% filled per hour (2Wh/hour) if you rotate the JOOS Orange to track the full sun on a very cold day. On a sunny day, if you just leave it in one place facing where the noon sun will be, you’ll likely average somewhere between 5% and 7.5% filled per hour.
When I deliberately flatted the Joos' internal battery and logged time-to-fully charge at home, it took just a couple minutes over 12 hours on a cloudless sunny day; I did move the panel three times over this period to track the sun. While atop my rear rack, I found the charging rate averaged just under 7%/hour (stopping periodically to check the unit's state-of-charge light against my stopwatch and the app loaded on my netbook), but that charging rate figure depends on so much. I changed direction of travel, was in and out of tree-shade, and the skies were variably cloudy but generally bright.
The Joos Orange isn't going to charge an iPad from flat in one go. According to Joos...
The JOOS Orange battery is roughly 80% the size of the iPad 1 and iPad 2 battery, and about half the size of the “new iPad” battery. Because of limitations with the charging circuitry on Apple’s iPad, some power is lost during the charging process. This results in the JOOS Orange providing a 60-70% charge on an iPad or iPad 2, and a 35-40% charge on a “new iPad.”
Of course, there is a limit on how many times a fully charged Joos Orange will replenish an iPhone battery...
A fully charged JOOS Orange will provide approximately 2.5 charges on an iPhone 3G, 3GS, 4, and 4S, and approximately 2 charges on an iPhone 5. Although the size of the JOOS Orange’s battery could, in theory, provide additional charges, limitations with the charging circuitry on Apple’s iPhone cause some power to be lost during the charging process.
Best,
Dan.
