Car Charger for Surface

Discussion in 'Microsoft' started by mgerbasio, Aug 17, 2017.

  1. mgerbasio

    mgerbasio Scribbler - Standard Member

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    I was going to get a power inverter for my car to provide a 120Vac outlet to charge my Surface. Anyone have a recommendation? Better to wait for the USB-C adapter from MS?
     
  2. Steve S

    Steve S Pen Pro - Senior Member Super Moderator

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    <<...I was going to get a power inverter for my car to provide a 120Vac outlet to charge my Surface. Anyone have a recommendation?..>>

    @mgerbasio : As you probably know, AC inverters come in two flavors, modified sine wave (think: stepped square wave) and true sine wave (smooth sinusoidal shape). The former are numerous and relatively inexpensive and the latter are rarer and relatively expensive. Of course, the question is: Is either type significantly better suited relative to your use case?

    In this instance, I think the answer is: No. An inexpensive, modified sine wave inverter will likely be satisfactory. Interestingly, Bestek shows up on many "best AC inverter" lists. Bestek makes a variety of models, but this one shows up a lot:

    https://www.amazon.com/BESTEK-Power...coding=UTF8&psc=1&refRID=KY78GP5N7NKSZFFMK25B

    I don't personally have any experience with Bestek, so I can't comment beyond what I've already said.

    If you believe that a true sine wave inverter might be desirable (perhaps because you think you might want to power other electronics that might be sensitive), then I would suggest that you consult with the folks at Don Rowe. I think that Samlex makes some good units:

    http://www.donrowe.com/75-to-900-Pure-Sine-Wave-s/1921.htm

    Remember that your accessory power outlet in your car is only good for 12V at ~10A (and some are a little dicey at that maximum current draw), so don't buy an inverter that will stress your car's electrical system (that is, stay in the 150W or less range).

    Good luck
     
  3. mgerbasio

    mgerbasio Scribbler - Standard Member

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    Thanks Steve, yes, that's exactly the issue: can I use modified sine wave vs true sine wave with the Surface. Obviously the cost, but the size difference is important as well. I assume with the separate power supply the Surface and most notebooks would be safe to use with the modified sine wave. Reading reviews for both types on Amazon, seems there are complaints.

    Amazon also carries this one which is a pure sine wave but again, complaints about using it with tablets and PCs.

    https://www.amazon.com/dp/B01DP9JE18/ref=psdc_583328_t3_B0191E8XWC
     
  4. Steve S

    Steve S Pen Pro - Senior Member Super Moderator

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    <<...can I use modified sine wave vs true sine wave with the Surface...>>

    ...Inverters are inherently noisy (i.e., EMI; electromagnetic interference). Consumer products seldom do a good job with filtering harmonics at the output or shielding the electronics. First, it's a demanding thing to do and second, it's expensive. That's why I tend to select industrial (or serious consumer) designs for this type of hardware. To the extent that inverters bleed EMI into whatever you are powering, trouble can ensue.

    <<...the size difference is important as well...>>

    ...Samlex makes a 120W true sine wave inverter with less than 3% THD that is as compact as any modified sine wave device. Of course, it is more expensive.

    Regardless of which way you elect to go, be sure that you can return the unit if you find it unacceptable...
     
  5. Steve S

    Steve S Pen Pro - Senior Member Super Moderator

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    A little more on inverter EMI. In my review of the Vagabond battery-powered true sine wave inverter, I wrote the following:

    "...In addition, all inverters produce a certain amount of radiated electronic "noise," and in some applications this radiated noise, or EMI (ElectroMagnetic Interference) can be problematic. The Mini is no different in this regard, but its radiated noise is reasonably well contained by internal metal shielding. Using an AM radio to "test," I was able to approach within about three feet of the Mini before I started to hear a really objectionable level of interference noise. That's pretty good! Within about two feet, the interference noise started to drown out the audio. So AM radios and inverters aren't a very good mix unless you can keep the two reasonably separated with a moderately long extension cord (maybe 6 feet?). Unfortunately, I don't have a spectrum analyzer, so I can't tell you at what frequency the EMI emissions peak but suffice to say that they are apparent across the AM radio band. FM, of course, is largely immune..."

    The full discussion thread is here:

    http://forum.tabletpcreview.com/threads/vagabond-mini-self-powered-ac-inverter-user-review.56197/
     
  6. mgerbasio

    mgerbasio Scribbler - Standard Member

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    Thanks again. I decided to wait and see what MS does for the USB-C adapter we've been promised. If I decide to get one, I'd probably go with the Samlex and find somewhere I can mount it in my car rather than pulling it out from the console compartment when I wanted to use it.
     
  7. Steve S

    Steve S Pen Pro - Senior Member Super Moderator

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    <<...I decided to wait and see what MS does for the USB-C adapter we've been promised...>>

    ...Well, it is "later this year," so I'm also waiting to see if Panos keeps his promise! However, I don't see the connection; the SP charger will work perfectly well (or should) plugged into either type of inverter...?
     
  8. mgerbasio

    mgerbasio Scribbler - Standard Member

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    There is also this
    http://forum.tabletpcreview.com/threads/car-charger-for-surface.72767/#post-505644

    which would be a better solution but with only 24 reviews, I'm reluctant to plug the Surface into it. I'd be using this while driving so I can charge my PC between job sites. A small USB-C connector would be a much better solution in terms of fan noise, EMI and size. If is was a need more than a want, I'd go with the modified sine wave inverter.
     
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