I get asked more and more about how to operate, charge, or otherwise power an iPad when away from civilization. Seems that the iPad is becoming a popular device for documenting expeditions. The iPad or the iPhone 4, but that is a topic for another post.
So, knowing the basics before actually getting my hands on an iPad, I knew that it uses a somewhat new twist on the USB standard... the iPad charger uses a 10 Watt USB port. The spec is 2.1 Amps at 5V. Not something that you find everywhere. Doing a little internet research quickly revealed work-arounds for PC's whose USB ports were not able to provide enough power to sync an iPad. Based on further research, I got the impression that any portable power system would need to be able to deliver the full 10 Watts in order for the iPad to be able to use the power at all. But, I was pleasantly surprised once I had an iPad & did some testing...
As it turns out, an iPad will draw power from any USB port that is Apple-friendly. This "Apple-friendly" description is the topic of yet another future blog post, but it essentially boils down to this: the USB port must be able to mimic a computer port with active data lines. Some USB chargers cut corners and are not designed to do this. So, consider that if a USB charger states that it is made for iPod or iPhone or is Apple-friendly, it will work with all USB devices. The iPad was happy to draw power from any of these USB ports, as long as they were capable of at least 500mA. The iPad would only "charge" from ports that were capable of getting close to the 2.1A spec.
With solar gadgets, it is often a matter of trial & error, especially when the manufacturer does not specifically state that their solar charger is Apple-friendly. So, I tested a variety of solar chargers that specifically state that they work with Apple devices, and tried them with the iPad.
Here are the results...
Performance: Power & Charge the iPad
PowerFilm USB+AA (using built-in USB port)
Brunton Sustain Battery (using 12V socket & Griffin PowerJolt USB adaptor)
Brunton Impel Battery (using 12V socket & Griffin PowerJolt USB adaptor)
Tekkeon 3450 Battery (using 12V socket & Griffin PowerJolt USB adaptor, or 2.1A USB port option)
Novuscell 50 Battery (using 12V socket & Griffin PowerJolt USB adaptor)
Novuscell 24 Battery (using 12V socket & Griffin PowerJolt USB adaptor)
NOTES: Any of the batteries listed above can be charged from standard 12V portable solar panels. A 5watt panel would be able to offset up to 10 hours of iPad use per day (summer month averages)
Performance: Power the iPad (but not able to charge)
Brunton Restore (via built-in USB port)
Brunton Freedom (via built-in USB port)
Brunton Inspire battery (via built-in USB port)
Brunton Sustain battery (via built-in USB port)
Brunton Impel battery (via built-in USB port)
Tekkeon 3450 battery (via built-in USB port)
Voltaic Amp (via built-in USB port)
Voltaic Fuse (via built-in USB port)
Voltaic V11 battery (via built-in USB port)
Solio Classic A (via built-in USB port)
Solio Mono A (via built-in USB port)
This is OK in my books because essentially you can easily create a solar-rechargeable external battery for the iPad. Presumably the iPad could be powered for a couple of hours a day from these devices without affecting the status of the iPad's own internal battery. This would be useful on trips of perhaps as long as 2 weeks. As long as iPod use is not excessive.
A note about solar-direct...
I did not attempt to plug the iPad directly into a solar panel, partly due to the fact that I do not like these "mercy-of-the-sun" type of configurations, partly because it was the middle of winter when I did these tests, and lastly because I am skeptical that anything less than a 5W panel in full sun would be able to 'power' the iPad, let along 'charge' it. But, I will certainly return to this topic this summer to see exactly how an iPad performs in this configuration.
I hope this note has been helpful. Please feel free to send any questions or comments.
8 comments:
Thanks for your write-up! I can't till your follow-up to see how it will perform under the summer sun.
Great review.
I wanted to add that I was able charge 1/3 of my ipad with the tekkeon mp 1550, with 4 X 2700 mah batteries. Although not rated as an ipad charger, the trick was powering off the ipad to charge it. With this said, I would think the Brunton inspire would be able to do the same.
Would love to hear from anyone who has tried it.
I have an Ipad adapter which output is 5.1V--2.1A.
I have an Olympus battery charger adapter output is 5.0V -- 500mA.
Question is can I charge my Olympus battery with the Apple adapter considering the difference in Amphs?
Will the camera XZ-1 be damaged?
Jim
Anonymous, If I understand your question, you would like to plug your Olympus charger into your Apple iPad USB port adaptor? If this is what you mean, then I believe it should not be a problem. Chargers are designed to take what they need from the source. ie you can plug an iPhone into a 2.1A iPad charger without any problem, because the phone will only use 1A of the 2.1A available. I hope that makes sense. If you could send the link to the Olympus charger you are using, I might be able to provide better advice.
I have been charging my iPad directly to a Brunton 26 solaris foldable panel, via a DC connector and a chinese cigarette adaptor that has two usb slots, one says iPad and the other iPhone. It charge my iPad within 3/4 hours depending on the sun. Works great.
Pablo
Interesting post by Moe. I would appreciate some insight on how to balance weight and power for a longer trip with maybe 20 days without power.
a. What weight budget should I expect?
b. Which of the solutions advertised above will give best results?
c. What are the pros and cons of using an intermediate buffer like the Brunton power banks in a solar system.
d. Cigarette adapters have a electrical characteristics that will waste about half the power from a solar panel. What alternatives work better?
For a longer trip, the balance of power is the same... balance the solar panel to the expected consumption of the device, and add a solar storage battery to get you through unexpected poor weather, and times when using devices for extended times. For example, if you wanted 2 hours a day from the iPad continuously, this equates to approx 1/4 of the iPad's battery capacity = approx 6 Watt-hours. Summer sun can replace this with something as small as a 2W panel. I would recommend the SunLINQ Mini, or preferably the SunLINQ Plus 4W. The power produced by these panels can be stored in the Voltaic V39 battery pack, or the Brunton ReSync battery... both will in turn deliver the 2.1A needed by the iPad.
The weight of either battery is 10oz, bringing the entire kit to just under 1 pound (450g).
Forgot to mention... I am assuming that the iPad is the only device being charged in the above scenario, and therefore I have kept the system to the 5V USB world for the sake of efficiency & to keep the system cost & size to a minimum. I would only recommend going to a 12V system if you had a 7.4V camera, or other device that needed the higher voltage.
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