Wouldn't to be easier to use the haptic engine to generate energy in response to movement when it's not being used to generate movement in response to energy?
The battery capacity of the Apple Watch is about 1 Watt-Hour.
A bike hooked up to an electric generator powered by a human in pretty good physical condition can generate about 100 watts.
So, riding such a bike for less than a minute would fully charge an Apple Watch.
The moral of my story is just this:
While it is true that humans cannot generate much electricity through physical activity compared to other modes of power generation, the amount of electricity needed by mobile electronics devices is actually pretty small. So it's not crazy to contemplate using kinetic energy from humans to charge mobile electronics.
I thought the Watch battery is 375 MAH, not 1,000 AH. My series 2 Watch last about two days, or a bit more, most of the time, as I'm not using the GPS too much. So it's just using a very small amount of power at any given moment. About 7.8 milliamperes per hour.
so, while I think this is impractical, it could actually work, and it certainly doesn't need a foot pound of energy to do it, just a small fraction of that. The Watch doesn't need to be charged fully by this, just incrementally.
"The 42mm Apple Watch battery has a capacity of 0.94Wh"
(just remember, to do this conversion you need to account for volts)
You're confusing watt hours with mAh.I just checked. I was wrong too. It's a 273 mAh battery at 4.35 VDC. The 7+ has a 2,750 MAH battery. So it's just a tenth of that. It's 1.03 watt hour at 3.77 VDC.
Wouldn't to be easier to use the haptic engine to generate energy in response to movement when it's not being used to generate movement in response to energy?
And how would that work? There are no moving parts in the haptic engine when not powered by the press, or click. Watch movement won't do anything.
The power generated from this would be so negligible to not be warranted and the tiny space used would better as battery.
There will likely come a day where the power required to perform many of the tasks of a smart watch will be reduced significantly. Your argument is like saying "there power generated by a portable battery would be so negligible that you couldn't make a portable computer that didn't require a power cord. Modern rechargeable battery technology has advanced (lead acid to lithium-Ion) and the power required by components (processors) and their heat production (fans) and spinning hard drives versus solid state... you can now have a laptop or portable device that can last the whole day.
If you make a smartwatch without a ton of features (GPS, WiFi) and instead rely on low power Bluetooth, OLED and other low power devices coming in the next 10 years... then this could make sense. You could wind up a spring powered flywheel and have it generate electricity as the tension is slowly released, powering the device. Imagine never needing to charge a smartwatch!
Wouldn't to be easier to use the haptic engine to generate energy in response to movement when it's not being used to generate movement in response to energy?
And how would that work? There are no moving parts in the haptic engine when not powered by the press, or click. Watch movement won't do anything.
oops sure tapic engine not haptic engine. Ifixit thinks there is one big moving part in there.
Seiko has been selling Kinetic watches for decades that use any wrist motion to spin a weighted magnetic rotor to charge a battery. They refined it with Kinetic Direct Drive, which also allows winding to contribute to the charge. Somebody should make a band that has such a system built in. I'm sure Seiko's patent has run out by now. Too bad Apple can't use solar power. My Pulsar solar watch has been running for the last 20 years on the same battery.
The power usage for standard watches is much lower. Seiko power draw is 0.71 micro-watts (millionth of a watt), solar calculators are at a similar level:
The Apple Watch uses about 50 milliwatts (thousandth of a watt) so about 70,000x more power than a standard watch. Calculators and standard watches can last years on tiny watch batteries whereas the Apple Watch lasts 1-2 days. Even if they had the same size batteries, that would be around 1000x difference.
There's a page here with some info about winding power:
To get a minute of Apple Watch usage, it would take 12 seconds of winding and this is a hand crank like on a wind up radio. They'd really have to make something like an arm band or knee pad that charged a spare battery using the leverage during everyday activity or the arm pad could be connected to the watch. Maybe shoe inserts that use pressure from the heel to charge a spare battery.
Solar would probably generate about 0.1W if the entire Apple Watch was a panel and that's if it was in direct sunlight. Having it round the bezel would be much less. You'd be better off plugging it in for a few minutes.
The best solution for hassle free charging of wearables will probably be getting the power from wireless signals. It can even come from stray wifi signals:
I am in agreement with many of the posters who feel the implementation of such a device is impractical. The energy generated from turning a crown would be quite small. Generating the power required would involve increasing the resistance such that winding the watch becomes too difficult to be practical. Conversely much longer winding times would be required again being impractical. Generating a watt hour of energy from a finger and thumb tip is asking a lot. Especially doing such on a daily basis.
It would make far sense to put a battery into band instead or a charging port on the watch so that one could change from an external battery, much like plugging the pencil into the iPad for a short period of time provides a meaningful duration of additional use.
Solar might be useful if the efficiency of conversion were substantially improved. Some form of charging would likely still be needed, but solar augmentation might be able to extend the life of the battery by a few hours.
The best alternatives would seem still to be to increase the capacity of a battery and decrease the energy required by the components.
Comments
If you make a smartwatch without a ton of features (GPS, WiFi) and instead rely on low power Bluetooth, OLED and other low power devices coming in the next 10 years... then this could make sense. You could wind up a spring powered flywheel and have it generate electricity as the tension is slowly released, powering the device. Imagine never needing to charge a smartwatch!
Ifixit thinks there is one big moving part in there.
https://d3nevzfk7ii3be.cloudfront.net/igi/2KCG6Oao4DERiLsf.medium
An apple pencil with physical activity charging would be great as well.
http://www.seiko-cleanenergy.com/watches/kinetic-1.html
http://world.casio.com/csr/env/product/history/
The Apple Watch uses about 50 milliwatts (thousandth of a watt) so about 70,000x more power than a standard watch. Calculators and standard watches can last years on tiny watch batteries whereas the Apple Watch lasts 1-2 days. Even if they had the same size batteries, that would be around 1000x difference.
There's a page here with some info about winding power:
http://www.trevorbaylisbrands.com/tbbnew/technology/winduppower.asp
To get a minute of Apple Watch usage, it would take 12 seconds of winding and this is a hand crank like on a wind up radio. They'd really have to make something like an arm band or knee pad that charged a spare battery using the leverage during everyday activity or the arm pad could be connected to the watch. Maybe shoe inserts that use pressure from the heel to charge a spare battery.
Solar would probably generate about 0.1W if the entire Apple Watch was a panel and that's if it was in direct sunlight. Having it round the bezel would be much less. You'd be better off plugging it in for a few minutes.
The best solution for hassle free charging of wearables will probably be getting the power from wireless signals. It can even come from stray wifi signals:
http://pratt.duke.edu/about/news/wireless-device-converts-lost-energy-electric-power
It would make far sense to put a battery into band instead or a charging port on the watch so that one could change from an external battery, much like plugging the pencil into the iPad for a short period of time provides a meaningful duration of additional use.
Solar might be useful if the efficiency of conversion were substantially improved. Some form of charging would likely still be needed, but solar augmentation might be able to extend the life of the battery by a few hours.
The best alternatives would seem still to be to increase the capacity of a battery and decrease the energy required by the components.