USB power to iPads

12 posts in this topic

Posted

Guys,

Just wanted to save some people from making the same mistake I made...it turns out that USB plugs are not universally the same Amperage. What does this mean?

It means that older iPhones and iPads can operate and charge on 1.2 amps, while newer iPads require 2.4 to fully charge the batteries.

How did I figure this out?

The hard way of course!  I wired two dual USB female ports into my wiring harness.  I tested it on my older iPad 2 and it worked like a champ, it was operating and charging while the aircraft battery was on.  Then a month later I bought two iPad Air 2 for my poor man's glass panel and after hooking things up I noticed that the batteries were not charging.  I read that some aftermarket USB cables wouldn't charge the newer iPads, so I bought new cables.  Guess What?  They still didn't charge!  So after further investigation I found the Amp requirements were the issue!

So once again, I learned the lesson the hard way for you guys! Your welcome and I'll make more :)

 

See ya,

Ron

image.thumb.jpeg.e61c875c71bb398059c250f

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Posted

Does anyone have a method of determining what the output is on a USB plug?

ive installed a dual USB plug on the mangy, but haven't used it yet.  The packaging didn't say anything...  

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Posted

The chargers should have a power output rating on them when your looking at the specs before you order them.  Every one that I have bought had the specs listed.  They should also be stamped on them some place.

 

:BC:

 

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Posted

Nice clean panel install too Mr!  Thanks for the warning to everyone!  :BC:

 

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Posted

Can you tell me what app you are using on the Ipads?  Thanks.

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Posted

RDavidson is right on, as much as Apples are loved by their aficionados, they are awful about how they want to be fed. The rules are fairly important: 1) Use only Apple certified cords, 2) use big power supplies, and 3) swap it all for new if the darn device slows down its charging rate, or rejects a charge.

If the cord has wires that are too thin, the voltage drop restricts the power delivered so the apple rejects the charge. Certified cords have the proper thickness and connections to avoid this problem.  For the Big power supply, seek at least 12 watts, which is 2.4 amps at 5 volts (USB is always 5 volts). Remember volts times amps equals watts. A computer USB port has 1 amp at 5 volts, so it is only 5 watts, and most apples will reject it.There are many car chargers with 3 to 6 amps at 5 volts, so they can have 15 watts to 30 watts to make your apple smile.

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Posted

Gregpro50 - the left iPad is running the iLevil "AHRS Utility" App, and the right side is using WingXPro.

I'm using an iLevil 2AW behind the dash to send Pitot Static/ADS-B in/engine info (from GRT-4000) via wifi to the iPads.

 

nlappos - thanks for explaining the Watts...I was confused as to how to calculate them, but you answered that!

 

thanks,

Ron

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Posted (edited)

On the same topic... While a lower amp plug might maintain the charge of an iPad (or just make it last longer) it will have the iPad battery working and therefore heating up. Not a problem in the winter but when it is already hot outside and with some direct sunlight the iPad will easily overheat and, as protection, power off... Been there, done that.. I was very happy to have both a good map and a river below me to follow until it cooled down again... NEVER rely on your iPad or other GPS as only navigation device. I now double with the same navigation app (and route) on my iPhone as well as paper map... 

It is easy nowadays to find appropriate converters (try amazon and search for "12 volt to usb 2amp") but note that converters with multiple sockets will divide the amps by the toys you connect... 

Note that direct sunlight on the iPad can still, even with an appropriate changer, make it overheat. I made a ventilated iPad support with outside air coming through a vacuum cleaner hose directly to the back plate of the support to keep the iPad cool. Don't forget to close the vent in the winter... Have had no issues since doing this. 

ventilated_ipad_support.thumb.jpg.e5ea3a

   

   

Edited by FredStork
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Posted

USB charger static

We do have another problem with using USB changed devices in flight. Most USB chargers, converting from 12 volts, are doing this with methods (don't ask me how...) that have a tendency to generate significant amount of static.

I installed a second USB charger in my plane and it makes it impossible to use the radio even when no device is connected to the charger... 
My first charger, still used for the iPad is not creating the much static. Unfortunately I dismantled it and have thrown away the casing so I have no way of identifying it to get a second one.

If you have a good (static free) experience from a  USB (from 12 volt) charger please post references in a reply to this string (or even better, direct link to the product on whatever web site you found it on). 

wite noice bis.gif

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Posted

Fred,

Unfortunately there isn't a reliable way to tell if a USB charger will cause static or not.  I've had two apparently identical ones, but purchased at different times, where one caused static, and the other did not.  Even with the same manufacturer, the same model, the internal components will vary over time.

They cause static because they are all now 'switching' power supplies, which means they turn the power on and off rapidly, and with other internal components to smooth out the electron flow this results in a lower output voltage.  The upside is they are way more efficient than the old 'resistor' power supplies since none of the input power is wasted.  The downside is if poorly made or designed, they generate a lot of EMI.  The cheapest ones also are 'on' all the time, even if nothing is plugged in and charging them.

I've had overall good experience with Rocketek, similar to this one:

http://www.amazon.com/Rocketek®-Charger-Adapter-Cigarette-Splitter/dp/B00HHT9FL2/ref=sr_1_27?ie=UTF8&qid=1463067102&sr=8-27&keywords=multi+usb+car+charger

The ones I bought were more expensive 2 years ago when I bought them, so they might not be as good now.

Mark

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Posted

...and to answer my own question...

I just bought a "aLLreLi 42W 5-Port Intelligent Car Charger Kit" (with a name like that you can't go wrong...)

While not mentioned at the US Amazon site, at the French version of Amazon they talk about the "superior quality components" and that it will not generate static or other disturbance to radio, Bluetooth, WiFi or 3G... Interesting difference... humm...  But I found no customer reviews mentioning radio interference (and this is a frequent comment) so for 14$ gave it a try...  

https://www.amazon.com/aLLreLi-Intelligent-Charger-Double-Sided-Devices/dp/B0122P1WFW/ref=cm_cr_arp_d_product_top?ie=UTF8 

It is very convenient with the long cord that can be cut and used for easy wiring. While the cigar lighter plug is converting to 5 volt the big box get 12 volt through the cord and has it's own converter.

In flight, I connected both my iPad and iPhone to the charger, verified that they were charging, and tried the radio. First I though the radio was dead, but no, there was just a perfect absence of static and other electric interference...

quietUSBcharger.jpg

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Posted

Thanks Fred. I just ordered one. If it doesn't work out, for the price I can always find a use for it.     Lou

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