Become a fan of Slashdot on Facebook


Forgot your password?
Power AT&T Iphone Apple

An Open Standard For Wireless Charging? 82

Charging portable devices without needing to carry a power adapter sounds handy, and it's slowly getting closer to widespread use. IPAQ2000 writes that AT&T, Google and Starbucks announced yesterday "that they have joined the Power Matters Alliance (PMA). Founded by Powermat Technologies and Procter & Gamble, the PMA's Honorary Chairman is Google's Vint Cerf – one of the fathers of the Internet — and its board now also includes AT&T, Duracell, Google and Starbucks. The U.S. Government's Energy Star and Federal Communications Commission – both PMA members — are board observers." (How does Starbucks come into it? They're "testing PMA-compatible Wireless Charging Spots in select Boston stores.")
This discussion has been archived. No new comments can be posted.

An Open Standard For Wireless Charging?

Comments Filter:
  • Is there any possibility that having access to an always on source of power would contribute to the overcharging of a battery? I guess what I'm asking is whether or not this would be equivalent to leaving a laptop plugged in to the wall for weeks and unplugging it only to find that the battery now has a maximum charge of two hours or something similar.
    • I have the original 15 year old battery in my laptop that still gives me about an hour and a half, down from maybe 2 hours when it was new. The real limit seems to be the number of cycles it goes through. I did unplug the machine when I wasn't using it. I believe the internal charger shuts off when the battery is full. Overcharging should not be an issue.

    • by marcansoft ( 727665 ) <<moc.tfosnacram> <ta> <rotceh>> on Tuesday October 30, 2012 @09:11AM (#41816775) Homepage

      That isn't caused by overcharging, it's caused by the battery simply being at 100% charge. Li-ion batteries like to be stored at 40% charge, and degrade much faster at 100%.

      The technical solution to this problem is a trivial firmware change to the charging controller to only charge the battery to 40%. However, I suspect nobody has done it because nobody has figured out how to get the users to switch to "40% maintenance charge mode" when always plugged in, without pissing them off when they run off and discover that their device is only 40% charged. The fundamental problem is being able to predict when the user will need to actually use the battery, and only fully charge it immediately prior.

      • Thinkpads can do this.
        I have my thinkpad battery set to charge to 80%.
        Yes, it means I have 20% less capacity - for the first year or so.
        After that, I actually have more, as it degrades _lots_ less fast.

        • Now you've left me wondering. Where is this setting? I certainly can't find it on the BIOS setup menu (ThinkPad X220).

        • by kullnd ( 760403 )
          I do allow my X220 to run full 100% charge, but it is rarely at 100% as I plug in most of the time and my battery is set to not start charging until it is below 70% ... As I move it from place to place and leave it in standby, and occasionally run on battery power, the battery slowly runs down to less than 70% and this setting keeps my battery from getting charge current more than an average of probably 4-5 times in a month. For my T510 that is always docked, the battery is set to start at 50% and stop
        • by fa2k ( 881632 )

          I actually set my thinkpad to start charging at 38 % and stop at 48 %. Then I charge it fully before flights and meetings where I don't have power. After 2.5 years, it claims to have 55.25 Wh max capacity left, while the design capacity is 56.16 Wh. I don't know if the reason it has held up so well is because I keep it half way charged or if it's just because I don't charge/discharge it that often.

      • There's lots of reasons why nobody has maximally-charged Li-Ion, Li-Po, Li-Fe batteries to 40%, but most of them have to do with form factors and battery costs. You want to use more of the battery. But complex devices do commonly lie to the user about battery charge status. On the Motorola Triplets and RAZR phones you could do quite a bit to the battery charge profiles to the point where if you tried hard enough you could probably set your battery on fire, especially if it was a cheap knockoff. Or you can l

    • This is a problem only when your mobile device is not mobile anymore.
      It will only be charged when it is stationary on a charging hotspot. Move it a few inches, and no charging.
      • by slim ( 1652 )

        Yeah. I don't find plugging in a charger a problem. I do like to use my device while it's charging.

      • Good point.

        I can still use my phone/tablet/ipod when they're plugged into the charger. Including making phone calls, playing games, etc.

        Can't do that if it needs to be sitting on/right next to the hotspot.

    • You're not plugging the battery directly into the power outlet! There's something called a chargeing controller between them. Its job is to sense whe the battery is charged and to cut power then. (Or throttle it to a sustaining charge). That's to prevent overcharging, because modern batteries don't simply overcharge and die silently, but rather tend to go with a bang. Literally.

  • by NotQuiteReal ( 608241 ) on Tuesday October 30, 2012 @09:00AM (#41816683) Journal
    I hope they put a switch on them, so you can turn them off, when not in use.

    I was surprised, a couple of years back, when I measured how much power unused wall-warts added up to. And don't even get me started on VCRs...
    • by OzPeter ( 195038 )

      I hope they put a switch on them, so you can turn them off, when not in use.

      Some countries have outlets that have integrated on/off switches. See AC power plugs and sockets []. Having this makes eliminating vampire power usage much easier. The only alternative I can see for the US is to use an outlet that is routed through a light switch (which is common in some rooms in US houses) or to use an external power board with its own isolation switch.

    • I was surprised, a couple of years back, when I measured how much power unused wall-warts added up to.

      Have you checked lately? I have a Kill-a-Watt meter, and the loads on modern chargers have gone way down in the past 10 years, especially when the load is disconnected.

    • How did you measure the power usage? If you used a cheap power meter that does not have accurate power factor measurement, then your measurements are completely useless. Idle switching power supplies have very low power usage, but a very low power factor, because they act as capacitive loads. This means that a naive current meter will measure all of that out-of-phase current and you'll end up with a grossly inflated power figure. A proper power meter measures both instantaneous voltage and current many time

      • [quote]Residential customers are usually charged for real power only[/quote]

        Yes, that's true, but power plants have to supply the "naive" amount of current. When you factor in losses due to delivery, it adds up. The point is, regardless of the power factor, it's worth saving electricity, if not for your pocketbook, then for the environment.

    • by Speare ( 84249 )
      I haven't seen the standard, but it'll likely include a handshake that's a lot like the NFC coils, perhaps even simpler. Check every 250ms with a very short low-power ping, and if there's a compliant device, start supplying higher power to the main coil for inductive charging.
  • by Coisiche ( 2000870 ) on Tuesday October 30, 2012 @09:01AM (#41816693)

    It seems slightly strange that when a lot of effort is devoted to improving power efficiency this is championed when it's just favouring convenience over efficiency. Maybe one day people will regret that.

    • I understand your concern. We would have to do the math, though, and contact the committee and our legislators for a wired and wireless standard that is energy efficient. The wireless method might be less efficient, but we also need to consider also how much energy is spent with the manufacturing of every new charger shipped with a phone or rechargeable device.
      I guess that a lot of people must have a lot of chargers around their homes, which they don't use anymore. Conscious people will recycle them, others

    • just favouring convenience over efficiency. Maybe one day people will regret that.

      That is the story of civilization writ large. You can get more food per acre if you cultivate by hand, using no machines ever except possibly an initial tilling. That takes a lot less energy but a lot more of it is in the form of labor. Lumber is now milled smooth at the cost of producing more sawdust both because it is more convenient for the builder to have smooth timbers but also because of the demand for shortcut materials like MDF. While some technologies do save energy, in general that is not the focu

  • Not wireless! You insensitive discharged clod!
    • I meant "with no electrical contact".
      "Wireless" is commonly used to mean "through EM radio emissions", as seen in WiFi.
  • How is it an open standard, when I need to join their organization to see the specs?

    • by vlm ( 69642 )

      How is it an open standard, when I need to join their organization to see the specs?

      I am mostly uninterested in transnational megacorp products but I REALLY want cheap gadgetry from the usual hardware hacker sources that's compatible with the overall wireless power system.

      Although I don't use arduinos, I'd like an arduino power shield, and I'd like a module about the size of a 9-volt battery to replace the battery inside my multi-meter, and and I'd like something the shape of some AA batteries with a really big capacitor to replace my remote control battery, and I'd like to retrofit my ham

      • If I could buy battery-format receivers which would go into my existing devices, I might pay pretty well for the ones I only use during the day when the sun is shining and the birds are chirping and the power is on. Problem is, I have few devices like that, and I'm not willing to pay a lot for a transmitter for few devices.

  • by Anonymous Coward

    Tesla was just born about a 100 years too soon to have his wireless ideas popularized, regardless of whether his methods were more or less efficient then the way forward this group plans to go. I'm personally glad to see this being researched. You can't make an inefficient process more efficient if you ignore it. Who knows what we'll learn and discover while researching this topic not to mention the potential device revolution when you're no longer limited in size by ports for power and data transfer. M

  • by jader3rd ( 2222716 ) on Tuesday October 30, 2012 @09:40AM (#41817049)
    I'm sure the public is going to love figuring out if a wireless charging pad is a Qi charging pad or a PMA charging pad.
    • Doesn't that new Nexus phone already have a Qi wireless charger? And then why is Google dibbling into PMA?

  • This is going to make comparing bills across carriers so much easier. Now we can compare apples-to-apples on the hidden "charges" in each company.
  • by denis-The-menace ( 471988 ) on Tuesday October 30, 2012 @09:56AM (#41817227) []

    Samsung and Nokia are already releasing phones with it, too.

    How many of these wireless charging standards do we need? (Oops, I'm gettin' it now...)

  • by Anonymous Coward

  • "First in the world' apparently :

    Free too...and free internet access too...and free wired power too.

Outside of a dog, a book is man's best friend. Inside of a dog, it is too dark to read.