Tuesday, January 20, 2015

Techy Tuesday - Tech You Can Use

How about boots that can recharge batteries

As technical advances have increased the amount of electronics that's useful to soldiers, the amount of batteries they need to carry has steadily increased, with some reports saying the typical soldier carries 20 pounds of batteries.  Now, a joint venture of Lockheed Martin and STC Footwear has produced boots that can replace some of those batteries carried.  In its current design, the Kinetic Boot is capable of generating up to 1.5 watts of power per foot to charge reusable batteries or connect directly to systems.
Previous solutions, such as solar-power chest panels and helmets, still added significant weight to soldiers’ uniforms, but the Kinetic Boot only adds 2 to 3 ounces of weight per boot—all while generating more energy. In a demonstration at the Marine Corps’ Experimental Forward Operating Base (ExFOB), a pair of Kinetic Boots was able to generate between 2 to 3 average watts of power...
I don't know the voltage available at those boots, but let's assume we can use it to charge a phone with no losses due to inefficiency.  A standard iPhone 5 original equipment battery, for example, is 1440 mA at 3.8V or 5.47 Watts.  It would take almost two hours of walking to completely replenish that battery.  Still, that's otherwise wasted energy, and it will add up in a day with a lot of walking.  I couldn't tell you how useful those 20 or so Watt*Hours produced by walking around would be.  
While the concept of harvesting energy from motion is not entirely new, efficiency has remained an ever-present problem. Further optimization of the boots will help achieve maximum power generation while ruggedizing the design for harsh military conditions. Enhanced ruggedized packaging will not only protect the boots’ components from environmental factors including dust and mud, but will also standardize the components’ positioning to increase reliability. 
I suppose these are a little while out, and even longer until they show up as surplus.  No idea of cost so they might be too much for the commercial market.  
U.S. Marines try out a Kinetic Boot prototype at ExFOB 2014.  (Photo courtesy of the US Marines.)

No references to Bennie and Jets. 


  1. Do we know the mechanism they use?
    I could think some methods:
    - micro hydroelectric thingy in a fluid filled insole?
    - thermoelectric ala the PowerPot? Probably not, since it's kinetic.
    - something with springs in the heels?
    - a little bellows and a tiny wind turbine? ;-)

  2. The battery problem is complex. I am trying to standardize my battery usage to AA batteries. Not possible. My cameras, cell phone, and some other techie stuff use their own batteries that are more or less unique to them. As a backup I have purchased a inexpensive USB rechargeable AA battery powered charger. SO I can recharge my odd batteries from AA's. I also have a inexpensive solar battery charger that will recharge 4 AA's (as well as other sizes). The next problem is that all the rechargable AA's are 1.2 volts and not 1.5 volts. I could go on but the point is we as well as the army need a better solution. Fewer battery sizes and equipment designed to operate correctly on the lower voltage of rechargable batteries.

  3. Anon 1442 raises a very good point. Batteries are a problem that anyone expecting to be off the grid needs to pay attention to. Standardizing on one or two sizes of battery makes sense, but like you say, AA batteries seem to be dropping in usage. I have no ideas how to address the lithium batteries like the CR123 cylindrical or C2032 coin batteries. There are rechargeable CR123s, but no rechargeable coins that I know of.

    And Weetabix - no, I wasn't able to find it on the Lock Mart website (I assume they did the tech and the other guys are shoe makers).

  4. Reminds one of the Jimmy shoes from Seinfeld.

  5. Given that they are walking and trickle-charging devices, a piezoelectric setup springs to mind.

  6. Heh. Bennie & the Jets.
    What, no mohair suit!?