How do I charge the Surface RT via a USB port or in a car?

This is correct. The Surface requires a 12 VDC feed to charge, a USB port is 5VDC. Although it may technically be able to build some sort of converter, it would require more current that a USB port could provide anyway.

MS currently also does not sell the charging cable as a separate piece, it is built into the transformer.

Either way, you'll never be able to charge the Surface off a PC.

You can however charge your phone, tablet, BT headset, or other devices using the Surface's USB port.

Greetings Kburgoyne,

You are correct, the new car charger adapter that was announced with the Surface 2 and Surface Pro 2, will work with ALL V1 & V2 Surface devices. 

(moderator edit)

Surface 3 and Surface Pro 3 have different power connectors

Greetings Cat2k1

Thank you for reaching out on us. Please continue to check Surface homepage, the Microsoft Store and your local retailer.

Thank you for posting and please let us know if you have anymore question, it would be our pleasure to assist you.

There is one available specifically for the Surface here: http://www.microsoftstore.com/store/msusa/en_US/pdp/Microsoft-Surface-Car-Charger-with-USB-Port/productID.291671000 

Hope that helps.

Boz9

its available right now athttp://www.microsoftstore.com/store/msusa/en_US/pdp/Microsoft-Surface-Car-Charger-with-USB-Port/productID.291671000?WT.mc_id=surface_RTM_carcharger

Try this ... 

▶ Microsoft Surface Car Charger with USB port via Microsoft Store

http://bit.ly/IAWxDk

I hope this helps!

David

Greetings all you frustrated Surface users who want a car charger.  Go onto the main Microsoft web site and look at the accessories for the Surface Pro 2.  There is a car charger listed.  I have no doubt it'll work for the Surface Pro 1.  Plus a car charger that works for the Pro should work just fine for the RT.  It also has a separate USB connector for charging a separate device that uses USB charging -- like your cell phone.

Greetings Leslie,

Sorry, there is currently no USB or Car charger designed for Surface.  Thank you for the feedback, I will pass the info to the appropriate team.

Please let us know if you have any other questions.

Thank you for posting.

Thanks for the response.  I know this sounds dumb...  but could i plug the USB from the wenger into the surface power charger and then connect it via the magnet to the surface?   i know it will take forever...but there is not many options for using either smartphone or tablet--no electricity...  

          

You cant... That wont work. You need to connect the 5V from the USB directly to the surface.

To do that, you have to know which of the 5 pins of the surface is + and -. Then you have to read the USB specifications to find out which pin is + and -.  :) And so on and so fort...

Just ask someone that know a bit about electronics to make an Surface-RT-to-USB-Power-Adaptor for you :)

If you have a power inverter in your car, that works. I just tested it as I had a drive to do and plugged it into my inverter during the drive and it charged just fine.

Not sure how well one of the smaller inverters would do as  I have had bad luck with those in the past charging electronics but my 400 watt one worked just fine.

As there are no alternative devices with the magnetic power connector needed the standard 110-240V AC adapter is the only option.

This in turn only leaves the option of a mains inverter in the car plugged into the lighter/accessory socket. At only 34w for the PSU the smallest inverter will do and as the PSU is a switched mode device a true sine wave inverter is not required.

No intelligent device with a USB "A" port such as in the Surface is able to be powered or charged by it. The devices you describe are fitted with USB "B" interfaces and are designed to take power from the port. The only exceptions are battery packs which frequently use the same port to be charged on as is then uses to power the USB device

You could plug something in to the Surface and it might charge it, not the other way round. What is actually lacking at the moment is an alternative to the supplied PSU which can connect to the magnetic power connector on the side of the Surface. As far as I know it is specific to the Surface and as such there would be copyright issues if a 3rd party charger was made and the use of one would probably invalidate the Warranty.

Ipads etc. can be charged via USB because the voltage requirements are defined by the USB standard, are not Host devices and the Surface is.

To put it simply, no.