I have been using Eneloop rechargeable batteries in my remotes for almost a year now. It's pretty awesome. Unlike NiMH or Li-Ion, they still have ~80%+ of their life after being charged and left on a shelf for 6 months. So they are a perfect application for this type of thing.
Only downside is that they're 1.2v and don't have enough power for some applications (like my lighted & battery-powered pepper mill. It was a gift.).
The shake&wake batteries are still awesome! I would love to have them. But Eneloop is here now, and very cost-effective.
Non-rechargeable 1.5v batteries only start at 1.5v. As you use them up, the voltage drops, going down to about 1v just before the battery poops out. The curve is not linear.
These batteries are down to 1.2v around 30-50% of the way through their life.
The rechargeable batteries start around 1.2v, but their discharge curve is much more level. They stay near 1.2v right up to the end.
If a device has trouble with rechargeable batteries because of the voltage, that device is also going to have problems with non-rechargeables, as the non-rechargeables spend at least half their service life below 1.2v.
The rechargeable batteries can confuse battery meters on some devices, though. If the device assumes non-rechargeable batteries, and then tries to estimate remaining battery by comparing the voltage to a typical non-rechanrgeable discharge curve, and you put rechargeable batteries in, the device is going to think they are starting out at 50-80%, and then is going to think they are draining very very slowly.
I would imagine that it won't generate enough power for a Wii controller. At the very least it would be bad user experience if for some reason your ability to interact with the game occasionally dropped out because you weren't in a 'vigorous' enough part of the game.
The wii controller is constantly using (relatively) large amounts energy to measure/process/send sensor data for however long you play. A remote on the other hand is intermittently transmitting short messages. My guess is that a large amount of the energy dissipated in the remote batteries is self-discharge, which makes putting a normal battery in one a little bit of a waste.
Looking at the power consumption of the various components in the Wiimote, the only thing that really eats a lot of energy is the radio. Data is not processed on the Wiimote. Looking at the data stream coming out, the only processed data is the camera at the front, which does it super-efficiently in an ASIC/DSP. Maybe a supercapacitor or normal battery in addition to one of those could store energy from the vigorous parts and allow for unbroken interaction. Games are already designed to pause on battery low, so it would not be critical, just annoying.
Sure, if they were in constant use, but they're used pretty sparingly. The bluetooth radio is on whenever the game hasn't been paused for a few minutes, and that dominates the power usage.
I know there's not serious data processing on the remote, but I count an analog to digital converter as processing.
The main reason why I don't think it would be suitable for a wii remote is that two AA batteries are supposed to last 45-60 hours depending on use. Remotes last much longer. Granted the wii remote is used more actively, I still think the non-reliability issue, even if only for pause, kills it as a power source.
In the end though, its probably the consumer's decision unless nintendo hard wires them in.
The Audio comes in as ADPCM, which does need to be decompressed and then goes through a DAC plus presumably some kind of amplification. ADPCM is easy to decode, but does still need a processor of some kind.
The proximity chargers for Wiimotes work really well. Don't even have to take off the outer rubber sleeve to use them. I'm all for reducing use of standard batteries, so at least the Wii still has a decent solution for this.
I had a shake-to-charge flashlight once. The movement to charge it would get you arrested for indecent exposure in the South of the US. OTOH, But it worked beautifully, and, yeah, no batteries needed.
The shake-to-charge flashlights appear to be a long tube with a coil of wire wrapped around it at the middle, with a permanent magnet with soft bumpers able to slide up and down the tube. You can feel the bump when the magnetic field hits the coil; I'm guessing that the rest of the circuitry consists of a bridge rectifier and a capacitor. (And an LED, of course.)
Presumably in the "battery", the LED is replaced with a power supply that can boost 0.8V or whatever up to 1.5V, or reduce 2V down to 1.5V when needed.
If they can produce this cheaply enough and if it doesn't need too much shaking to make it work it could revolutionize children's toys. A lot of kids carry around their toys a lot in comparison to the amount of time the electrical parts are actually in use, so there should be ample charging time. Lots of toys only need their batteries replacing every six months to a year, so I assume they are fairly low drain and would suit this well.
Edit: Battery compartments that children cannot get into a also no doubt a part of the manufacturing cost, so batteries that never need replacing that can truly be built into the toy wouldn't need battery compartments and could simplify design.
I thought this was a terrible idea at first, because a significant portion of television viewing time is spent at night time.
However, if the cells were on the front of the remote and were good enough that they could power it based upon only the glow from the TV, that would be great. You're already pointing the remote that direction.
this is clever. but the question becomes how much does it need to be shaken. if its just a few shakes, cool. if its tons of shaking to change channels, people will get annoyed (remember, people are lazy as f#$k)
We did this for one of our university design projects (back in 2007). With a rudimentary prototype we created in a couple months, we were able to charge an LED light for a second after 30 seconds of shaking the battery.
So what I'd like to know for this is the same thing, how long would I have to shake the remote to get a single button push?
I got 2 free samples AA batteries from http://www.USBcell.com in 2007 during their demo (at DEMO), and I've been using them ever since to this date with my wireless Microsoft mouse. I found out that my mouse will work with just 1 AA, so while one is being used, I stick the other in the USB drive (to charge), and I just swap when the one in the mouse runs out. And it's been 3 years!!!
No shaking required.
Whenever I replace the AA from my mouse with the one I just unplugged from the USB drive, I time how fast I can "reload" <-- used to play Time Crisis 1 and 2 obsessively back in high school :D
The magnet in a shake-light is large, and the coil probably has at least a hundred turns of wire. A magnet and coil that can fit into a battery is going to be much smaller-- and then you still have to fit in the rectifier and capacitor.
I think it will be very effective. However, the control options will be limited with a shake operation.
Though, the innovative thinking needs a hats off..
Only downside is that they're 1.2v and don't have enough power for some applications (like my lighted & battery-powered pepper mill. It was a gift.).
The shake&wake batteries are still awesome! I would love to have them. But Eneloop is here now, and very cost-effective.