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Discussion Starter · #1 ·
Howdy, i'm just trying to get a USB port in my dash to power my iPhone 12 with an apple magsafe puck and wonder if anyone can advise on the best route. I didn't do my research well enough and purchased a 12V to 5V DC Converter (3A 15W... shown below) from Amazon... is there anything similar that can power do 9v 20w (what the apple magsafe requires for full speed charging)?

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I thought I'd get at least some power with this little converter but no dice. I think the reason is because the small USB-C to USB-A adapter i have between the iPhone charger and the converter's USB port is only for data.... . Not 100% on that but I had hoped the phone should at least trickle charge a bit. That it doesn't makes me think it's the adapter... so instead of fixing that issue I'm just checking to see if there's a proper solution (ie. install a usb port that has full charging speed)

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I thought Soundman might have a solution with his iPad install kits... and he does have 3 wiring kits, but it looks like they all use the cigarette lighter. I want this to be permanent, and hidden.... cables hanging out of the dash lighter just won't do! I sent them an email to ask if they have a wiring kit that doesn't use the lighter... no response. So... I wonder if anyone here can advise on the best way to get full speed usb-c / usb-a ports in the dash? Are folks just going to AC behind the dash and plugging in a normal wall adapter?

Cheers!
 

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If you're into diy type projects and don't mind a little soldering, the following would probably work:


Its output is adjustable and can easily supply 3 Amps @ 9 Volts for nearly 30 Watts (more if you enhance the heatsink). You'd need to put it in some type of enclosure along with getting the applicable connectors for your device(s) but I bet you could throw it all together for under $30 USD if you tried. You'd want to connect it to a switched accessory 12 Volt line that follows the ignition, which can also supply at least 5 Amps. The cigarette lighter feed wire would work well. Finally, don't forget to fuse the input to your project at approx. 5 Amps.
 

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Discussion Starter · #3 ·
Hmmmm yes, that does look like it would do the job and I'm perfectly happy with DIY. Thanks man, much appreciated, I will probably do this, unless.........

What do you think would happen if I tried to feed the magsafe puck with 12v? Forget the step down to 9v altogether and solder up a fused female usb-c power-only connector and plug the puck into it directly. I wonder if the apple puck would complain about that.... don't wanna come out to a pile of ashes in the morning. =]
 

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My guess is it might tolerate the extra 3 Volts with the engine off but it's not worth finding out! Especially since the vehicle voltage will fluctuate between 12 and 14.5 Volts with the engine running. Odds are you'd fry it! To be safe, try and stay within +- 5% of the target voltage that the device requires. High current buck converters like the one I linked to are pretty cheap and easy to work with. One of those with a proper fuse and you should be safe. As a disclaimer however, I'd test it out on the bench, under full load for your application. That way you know what to expect for things like heat dissipation, etc. Those converters are pretty efficient but they do still generate some amount of heat. My guess is it will get warm but not so hot that you can't touch it. If it does, you'll want to thermally couple the heatsink to something larger that can wick away the heat.
 

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Discussion Starter · #5 ·
Yep understood completely, everything you've said makes perfectly logical sense. Again... much appreciated, I'll let you know how it goes!
 

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Just use a cigarette lighter socket with flying leads and wire it behind the dash to an ignition supply, I use lots of them at work 👍🏼
Or get one from the breakers from any car and use spade connectors or solder wires to the rear of the socket

A generic 9v adaptor may not provide the charging you desire, the chargers are designed to charge at a variety of voltages and be adaptive, I am not sure a standard 9v output charger would do why you require

you would be better off buying a cigarette lighter charger and mounting it as said in a dummy cigarette lighter socket behind the dash 👍🏼
 

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I dabbled down this road a bit myself and found out that simply having the 30W (3A USB-C) isn't adequate. I'm pretty sure it must be spec'd for "PD 3.0". I tried one of the buck converters like you had listed and it didn't do the trick, but bought this (see link below) before having success w/MagSafe.

Amazon.com: 48W USB C Car Charger Socket, Qidoe 12V/24V Dual USB Outlet PD & QC 3.0 Car Socket with LED Voltmeter and ON/Off Switch Fast Car Charger for Car, Boat, Marine, Bus, Truck, Golf, RV, Motorcycle
 
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