

Brother to replace AA & AAA with shake-to-wake batteries - ukdm
http://www.geek.com/articles/gadgets/brother-to-replace-aa-aaa-with-shake-to-wake-batteries-20100716/

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apinstein
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.

~~~
tzs
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.

There are some good graphs showing discharge curves here:
<http://www.powerstream.com/AA-tests.htm>

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.

~~~
apinstein
It's a good point, but in practice I have found some devices won't even power
on with the 1.2v batteries.

A good example being the Microsoft Bluetooth Mobile Keyboard 6000. The
batteries don't last for 5 minutes even. Alkaline batteries last for months.

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Kliment
Sounds well-suited for the Wii controller. It's like shake to reload in old
arcade games.

~~~
secretasiandan
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.

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Kliment
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.

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axod

      * Loudspeaker
      * Vibration
    

Those 2 functions in the wiimote eat battery.

~~~
blasdel
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.

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DirtyAndy
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.

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ovi256
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.

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kragen
I'm guessing these batteries are the same thing.

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.

~~~
ja27
Make your own mini shake light: <http://www.instructables.com/id/Shake-it-
like-a-Tic-Tac!/>

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adolph
So this turns anything battery powered into a shake-weight?

Cultural reference point (maybe not safe for your work):
[http://www.hulu.com/watch/143264/saturday-night-live-
shake-w...](http://www.hulu.com/watch/143264/saturday-night-live-shake-weight-
dvd)

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ollysb
Love it, how many times have you seen someone shaking and hitting something in
a vain attempt to make it work?

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someone_here
It would be nice if remotes were solar charged, like pocket calculators.

~~~
subwindow
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.

~~~
someone_here
And it would be charging all the time, too, not just when you're using it.

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brianbreslin
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)

~~~
barredo
Hung the remote to an elastic cord, shake it, and let physics do their work.

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thinker
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?

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thinker
Found our poster for this project: [http://sphotos.ak.fbcdn.net/hphotos-ak-
ash2/hs031.ash2/34894...](http://sphotos.ak.fbcdn.net/hphotos-ak-
ash2/hs031.ash2/34894_1544343691951_1335774917_1451059_3113184_n.jpg)

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blhack
YES! I was just thinking of something like this last night for things like
car-key transmitters and the like.

Lots of stuff (like remotes) sits around not being used except for a few
seconds every couple of hours (or days).

Really awesome, good job, Brother.

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jayliew
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

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sbierwagen
I'm not sure how practical this will be.

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.

All of this in the AAA form factor? Implausible.

~~~
ja27
Not really. You can see a smaller homemade version of the shake light here:
<http://www.instructables.com/id/Shake-it-like-a-Tic-Tac!/>

That could almost fit in a AAA. The capacitor or battery would be the largest
part after the magnet/coil mechanism.

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r3570r3
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..

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dpcan
Tesla should put these in the shocks of their cars and they could self charge
as you bounce down the road :)

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subwindow
That sounds very useful, but what's the price? I doubt it will catch on if it
is $10 per "battery".

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moe
If that battery never needs replacement I would pay even more than $10 for it.

(And assuming it has a reasonable shake/runtime ratio)

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pbhjpbhj
Is anyone else thinking that they could pair these with teenage boys with
fleshlights and power the planet?

