charging cable with a usb on the other end?
- Thread starter sere
- Start date
goodintentions
Active Member
Um... what is the amperage and voltage of your USB's output? No, there ain't any. But it is not difficult to make your own, assuming your usb output has the right voltage and amp.
malberttoo
Well-Known Member
Hi Sere, welcome to the forum!
I have never seen a charging cable for the SP3 with a USB connector on the end. I have a feeling that at this time the only chargers out there are power bricks, and the automobile cigarette lighter chargers.
If you find one, let us know!
Sounds like you want a straight USB extension cable.
I doubt you will see anyone make a charger with a dual head USB/Power Cable. In everyday use it would be unwieldy and in the way except for the few times it was needed. The demand for this as a normal setup would be pretty low.
I doubt you will see anyone make a charger with a dual head USB/Power Cable. In everyday use it would be unwieldy and in the way except for the few times it was needed. The demand for this as a normal setup would be pretty low.
surfdock
Active Member
Although probably not what the OP wants, there is a third party power supply that brings the USB charging receptacle out to a few inches away from the main tablet power connector rather than on the brick like the OEM power supply. Here is the car version:
http://www.amazon.com/Nuosi-Deng-Po...r=8-2&keywords=surface pro 3 power supply usb
And the mains/wall-plug version:
http://www.amazon.com/Nuosi-Deng-Po...ref=sr_1_2?s=pc&ie=UTF8&qid=1420227205&sr=1-2
OEM version is like this:
=------------[||-usb-||]----------------------------------------tablet
3rd-party is like this:
=------------[||||||||||]--------------------------usb----------tablet
=======================
As for using the 5V USB source to output 12V to charge the tablet, you need a 5V->12V DC-DC boost step up converter of which many are available from electronics suppliers on ebay, aliexpress, dx.com etc. Just search for "5V boost converter" here is a good example:
http://www.ebay.com/itm/30W-DC-5V-t...034?pt=LH_DefaultDomain_0&hash=item3cdf0a0ea2
Some like this one have a preset voltage. Others have an adjustment screw to change the voltage so you need a multimeter to set it right and you'll want to check the voltage again during charging. You'll need to supply the USB connector to solder on the board as well as a generic 12V barrel-style output receptacle and a generic Surface Pro 12V charging cable as mentioned in many other posts on this forum. Finally you'll probably want to put the whole thing in a small plastic electronic project box.
One issue you'll run into is that most USB will only output 5v@ 2.1amps or less. That's only 10.5 watts. The Surface Pro 3 charger is rated at 36 watts so it may not work at all. I know the older Surface Pro 1 and Surface Pro 2 would accept a lower current charge from the smaller Surface RT chargers and just take longer to charge. I'm not sure about the Surface Pro 3 - it may reject a lower current. If you had two USB 2.1amp receptacles could you run them in parallel as an input to the boost converter? Maybe - it depends on the configuration of the USB outputs. It would be a fun project, but probably not worth the trouble.
http://www.amazon.com/Nuosi-Deng-Po...r=8-2&keywords=surface pro 3 power supply usb
And the mains/wall-plug version:
http://www.amazon.com/Nuosi-Deng-Po...ref=sr_1_2?s=pc&ie=UTF8&qid=1420227205&sr=1-2
OEM version is like this:
=------------[||-usb-||]----------------------------------------tablet
3rd-party is like this:
=------------[||||||||||]--------------------------usb----------tablet
=======================
As for using the 5V USB source to output 12V to charge the tablet, you need a 5V->12V DC-DC boost step up converter of which many are available from electronics suppliers on ebay, aliexpress, dx.com etc. Just search for "5V boost converter" here is a good example:
http://www.ebay.com/itm/30W-DC-5V-t...034?pt=LH_DefaultDomain_0&hash=item3cdf0a0ea2
Some like this one have a preset voltage. Others have an adjustment screw to change the voltage so you need a multimeter to set it right and you'll want to check the voltage again during charging. You'll need to supply the USB connector to solder on the board as well as a generic 12V barrel-style output receptacle and a generic Surface Pro 12V charging cable as mentioned in many other posts on this forum. Finally you'll probably want to put the whole thing in a small plastic electronic project box.
One issue you'll run into is that most USB will only output 5v@ 2.1amps or less. That's only 10.5 watts. The Surface Pro 3 charger is rated at 36 watts so it may not work at all. I know the older Surface Pro 1 and Surface Pro 2 would accept a lower current charge from the smaller Surface RT chargers and just take longer to charge. I'm not sure about the Surface Pro 3 - it may reject a lower current. If you had two USB 2.1amp receptacles could you run them in parallel as an input to the boost converter? Maybe - it depends on the configuration of the USB outputs. It would be a fun project, but probably not worth the trouble.
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It seems people are confused here.
Sere is just looking for what most of us would like to exist, to be able to use a power bank via a usb cable, not a DC cable (the batterie that have DC output are typically on the expensive side, given that it's a big battery designed to recharge things like laptops). As Nicola states, this doesn't exist because the surface uses 12v and USB is 5v
Sere is just looking for what most of us would like to exist, to be able to use a power bank via a usb cable, not a DC cable (the batterie that have DC output are typically on the expensive side, given that it's a big battery designed to recharge things like laptops). As Nicola states, this doesn't exist because the surface uses 12v and USB is 5v
goodintentions
Active Member
Ditto on hughile's post above.
Also, FYI people, if you plug the surface into something that outputs 5V, you're going to get the trickle charge effect where it takes like a week to charge up your device.
And no, the opposite isn't true. If you plug a 5 V device into something that outputs 12V, you're going to kill your device.
Also, FYI people, if you plug the surface into something that outputs 5V, you're going to get the trickle charge effect where it takes like a week to charge up your device.
And no, the opposite isn't true. If you plug a 5 V device into something that outputs 12V, you're going to kill your device.
Thanks for the welcome. I spoke to Microsoft, and they said as far as they know it doesn't exist, but they couldn't go very far, because all their access to sites selling non-Microsoft technology is blocked.
You can't trickle charge the Surface Pro's via USB. The necessary circuitry is simply not there.
