Thread: Charging iphone and ipad from 12v USB - frustrated

According to this site there needs to be a voltage on pins 2 and 3 before an iDevice will start charging.

How to make your own iPad 2 USB Charger (DIY iPad 2 USB Charger)

Check the update at the bottom of the page in particular as there is additional information suggesting the voltage on the data pins indicates may be used to signal the amp rating of the supply.

Also if you check out this page selling the same Fulree dual plug dc-dc converter linked in the first post

DC/DC Converter step down 12V to 5V 3A 15W Dual Female USB A Plug-in Switching Power Supply from Consumer Electronics on Aliexpress.com

you'll see the line

>Output voltage: 5V, 2 type A USB female Ports(for USB charging ports(can't be used for iphone).

Add:

This page has a breakdown of voltages required on the data pins for each supply rating.

Choosing USB Pin Voltages for iPhones and iPads – Update for iPhone 5 | Voltaic Systems – Solar DIY and Device Charging

And a couple of diy articles on how to modify cheap ass chargers to provide correct voltages:

Modify a cheap USB charger to feed an iPod, iPhone or Samsung Galaxy

How to get your iPod to charge with your homemade charger.

I've decided to give one of these a go....

I have a dual USB socket that plugs into a cigarette lighter, it has one 500mA USB and one 1000mA, the apple devices only charge on the 1000mA one.

Originally Posted by Barefoot Dave

G'day mate.
I am led to believe Apple added a little feature in its' latest update.
The devices now ignore ALLnon-apple add ons such as battery packs etc, cool eh?
My car charger is also junk now

You've been led down the garden path then.

I have a multitude of add ons and all of them function fine.

As Offtrack posted, real power is needed to run them.

I bought one of these units to power usb devices:

CPT-C5 power converter 12V/24V switch to 5V [POW01161B] - $8.50 : Seeed Studio Bazaar, Boost ideas, extend the reach

I have to admit I haven't got around to installing as yet. Obviously it's going to require a small amount of extra circuitry along the lines of the information above but it should handle charging two 2.1A devices without too much trouble.

Got a Belkin charger that charges my iPad in the car no problem.

FWIW I've got other car chargers that don't charge my Samsung S3 phone, need a higher rated charger there as well. It's not just Apple

See option 2 in this link .... I haven't tested it yet but it will hopefully provide the simplest (albeit not the most ideal) solution - happy to switch it off while it charges.

I've got 3 different types of USB charger and the ipad and IPhones that get plugged into them all have the latest updates and they work fine...