Why can’t we apply hybrid power tech to mobile devices?


Hybrid_screenFULL DISCLOSURE: I have no technical background in how rechargeable batteries or hybrid auto technology works. Y’all are smarter than me, so I’m hoping you can set me straight!

I had a thought about mobile tech while driving my hybrid auto. We bought a 2006 Toyota Highlander Hybrid last summer and we’re loving it. Having the 288V battery recharge as we coast, go downhill or brake is simply amazing; plus you can watch it all happen on the 7-inch touchscreen. My thought was: how can we apply this tech to mobile devices since one of the most limiting factors is power capacity?

The basic regeneration of power in hybrid vehicle comes from a mechanism attached to the wheels. As the wheels turn, they generate power that’s captured and returned to the second battery; my guess is that this is classified as kinetic energy. The primary battery is a standard car battery just like non-hybrids have; it’s the monster 288V battery under the back seat that gets recharged.

We’ve essentially got a "wheel" in today’s mobile devices; that hard drive spins like a banshee 95% of the time, right? Today we power the hard drive and other components with a standard battery, but what if we added a secondary battery? Could the first battery spin the hard drive so that we could recapture some of that energy to a second battery?

I’m sure there are a hundred technical reasons we can’t do this and I’m expecting those of you brighter than me to tell me what they are. I’ll consider this a learning experience, really. Still, somthing’s nagging at me here that there must be some way to apply this train of thought. I realize that the components needed for this might be larger than the space we have to work with, but it’s only a matter of time before that constraint disappears. I say: let’s make the hard drive a "power pass-through" to net another hour of so of device usage through a secondary battery…thoughts?



Tysoc (USN Electronics Technician)

Well i am no huge expert on this topic, however the years i have spent in the field it is my hobby to find the wasted energy that we humans produce and find a use for myself from it. Do you know how much voltage is wasted daily in any one place at one time? While you are sitting at home right now surfing the internet every wireless device you own in your house, the local radio stations, RF based TV stations, your neighbors wireless router all generating voltages running through the air at the speed of light. As well as all the light in your house is primarily all on the visible light spectrum. A small device in your mobile tech to store the electricity that the RF energy generates when it hits your antenna would not increase your weight by any significant amount and the plastic case… hmmm, well lets think about this one, we own cell phones with useless plastic cases that serve no purpose in life other than the protection of your electronics, so why not make that plastic clear, then under every surface of the whole phone is a small PV panel? Look at your phone right now and imagine that on every place that you see plastic case instead of pink, gray or black whatever color you see now imagine it is a PV panel (PV is Photovoltaic a.k.a. Solar panel) now that kind of technology combined with the RF converter could supplement your phones battery life dramatically and if you are a someone like me that uses it about once a day, may never have to charge your phone. I am no engineer, however i am a huge fan of Rudolf Claussius and the entire thermodynamics/energy field. Besides, solar is not the way to go in the solar field anyways, PV panels run at a maximum efficiency of 15%. If you have any questions feel free to email me at tysoc_kio@yahoo.com with the topic THERMODYNAMICS in bold in the subject line.

no in purtickyouler

Hmmmm….I think we should add a stirling engine-type panel to the keypad, which would connect to a flywheel encased in a vacuum sealed enclosure where it’s geared to a micro-generator (see izusu nano-tech websites). Thermo couplers in the mic area for heated arguments. Solar cell covered dish antennas for better reception + more charge, and a little hand winding attachment to the generator as well (for when you feel cranky), and we might have the ultimate “off-the-grid” phone.


Looks like I missed a cool conversation, but I still have to wonder if the kinetic energy we apply by using the digitizers might be of use, added to whatever else could be found in a mobile.

Davey A in the UK

As a Toyota Master Service Manager and an owner of a mobile device, I am interested in both.Unfortunatley there is not enough kinetic energy in a mobile device unless you hold it out of the window of your vehicle with a fan and solar cell attached whilst moving or maybe drop it from a great height with the fan attached or even maybe,just maybe use a car adapter on your hybrid.Therefore using your Toyota’s kinetic energy.

Mark Sumimoto (Sumocat)

Uh, Kevin, that “mechanism” attached to the wheels that captures the kinetic energy is the electric motor. An electric motor is essentially the same as an electric generator, depending on which way the current is flowing. As the hybrid decelerates, it pushes electrons back through the motor turning it into a generator. Of course, a hard drive also spins using an electric motor, so the concept could work. Not sure the return you’d get from a decelerating hard drive would be worth the effort. Doesn’t carry the same mass as a moving vehicle.


What you are unfortunately facing here is the Laws of Thermodynamics, and you can’t win. You’re basically suggesting a sort of “perpetual motion machine.” If you were to put a generator on the hard disk (or fan or anything else being powered by the battery), you add electromotive resistance (why the hybrid can use the generate as a brake), which requires the battery to provide even more current to keep the disk at operating speed. So, while you would actually generate juice in another battery, you would do so at the cost of extra drain on the primary battery. Worse, because of friction (physics, thermodynamics and all that stuff), you ultimately come out behind where you started. It also doesn’t matter how many batteries you have — it’s a closed system.
Why does the hybrid car work? As was pointed out, you are recycling kinetic energy (from braking or coasting) back to electrical energy. However, this isn’t enough to keep you going indefinitely; you need the gas engine to keep things running. And when you run out of gas and deplete the battery, you are done.
The idea about using kinetic energy from body motion, as some watches do, will work, sort of — the source is outside the “system” (when defined as the machine). Of course, the larger system (you + the machine) will run out of energy eventually, too… The watch is viable because the energy generated by walking is almost certain to exceed that needed by the watch (i.e. don’t bother if you are a couch potato). Pretty sure the same would not be true in UMPC usage scenarios — much (much much) higher energy requirement, and I don’t know too many people who would swing them back and forth enough to get much recharge. The answer is better batteries and lower power consumption.

Raphael Salgado

I ordered a Scott eVest with the solar panel add-on on the back, thinking I’d be with a Windows Mobile or other 5V device for a while, but it looks like it won’t be able to power my 16V Sony UX180P. :( But, I still think solar energy is the way to go. Every battery (or flat surface on a mobile device) should have a solar cell on it. At least it’ll get SOMETHING.


Your hybrid’s battery pack is charged from the excess energy that your gasoline engine produces (i.e., when you coast) and whenever you break it is actually using the generator to slow down the car while charging the car.

You could in theory use a generator to recapture some of the energy wasted when the hard disk spins down, but I don’t think that would make a huge difference in battery life (and would certainly add to the weight of the device). The way to go, IMO, is to not have a spinning drive at all.


the thing with the hard drive is that it goes to search for specific pieces of information and then stops , it doesnt just keep spinning like a car. it just does as much as needs to be done.


You know the heat those drives generate? That’s the wasted energy that needs to be harnessed.


Don’t forget the heat that is generated…if we can only harness that energy and use it for steam propulsion….



If your hard disk is spinning like a banshee all of the time (thrashing) you have PROBLEMS! :D I know it spins all of the time, but to be honest anything you would add to generate power would be slowing the disk down. We do have something better…..

How about the following….

1. Put a generator on the fans.
2. How about a flip out Solar Cell? Build it into the lid of your laptop.
3. A hand crank!
4. Fuel cells.

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