Half a croissant, on a plate, with a sign in front of it saying '50c'
h a l f b a k e r y
It might be better to just get another gerbil.

idea: add, search, annotate, link, view, overview, recent, by name, random

meta: news, help, about, links, report a problem

account: browse anonymously, or get an account and write.



Clockwork Battery

Retro Device Retrofit
  [vote for,

Picture an AA battery with a keyhole. Insertion and rotation of a key winds a little mechanism that provides a few mA, at 1.5 volts, for maybe a minute or so.

Formerly battery-powered toys and gadgets can now be converted to wind-up.

mitxela, Apr 27 2015

bit of prior art Torque_20Battery
skipping the "convert to electricity and back again" stages. [FlyingToaster, Apr 27 2015]

Alternative Energy Storage Methods http://www.mpoweruk.com/alternatives.htm
[hippo, Apr 27 2015]

Wind-up battery design http://gizmodo.com/...attery-to-charge-up
This uses a fold-out crank to do the wind-y bit. [tatterdemalion, Apr 27 2015]

Wind-up double A http://quintessenti...p-double-a-battery/
This one works by twisting the case. [tatterdemalion, Apr 27 2015]


       I like this.   

       How much energy can be stored in a AA-size battery? I'm guesstimating that the spring might take a force of about 10N (1kg) to wind, and that the total travel made by the key might be 1m, giving you 10J of energy.   

       If the device draws 10mA @1.5V, that's 15mW of power, meaning that it would run for 60 hours (or, allowing for losses, maybe 10-20 hours) which is not insignificant!
MaxwellBuchanan, Apr 27 2015

       I can see survivalists going nuts over these.
Voice, Apr 27 2015

       "Aha!" says yer friendly, neighbourhood aerial bread braiser, "I can mfd this !"... but I can't 'cuz they're different... [+] <link>
FlyingToaster, Apr 27 2015

       Neet idea of you loose the keyhole and just have a twisty portion that you turn like when you're taking the twist top off of a bottle.
doctorremulac3, Apr 27 2015

       //Neet idea of you loose the keyhole and just have a twisty portion...   

       (suspects the good doctor has imbibed of the contents of said bottle..)
not_morrison_rm, Apr 27 2015

       [Max-B] The linked article says the Trevor Bayliss wind-up battery gives 3V at 55-60mW for 40 minutes which is within an order of magnitude of orders of magnitude of what you were saying.
hippo, Apr 27 2015

       Am I good or am I good?*   

MaxwellBuchanan, Apr 27 2015

       "AA" --why not also "AAA" and "C" and "D" cell-sizes?
Vernon, Apr 27 2015

       nice idea +
xandram, Apr 27 2015

       The Energizer bunny is gonna be pissed. (+)   

       Very clever!
the porpoise, Apr 27 2015

       Yeah, yeah, you could make it last for hours, and it could be wound by twisting it... but I'm pretty sure it would be best if it needs a key, and only lasts a minute.   

       [Vernon] Haha, you're mad!
mitxela, Apr 27 2015

       I love the thought of the teeny key. Now I'll need a wee bitty key chain to keep it on. Wow.
blissmiss, Apr 27 2015

       I want a battery powered winding device to go with it.   

       Lots of prior art on this (links).
tatterdemalion, Apr 27 2015

       Why do all of these things use hand cranks, twisting or shaking? What's needed is a pull cord similar to the one used to start a lawn-mower. Design the battery to come apart into two pieces to form handles. Using a string allows a nice long power stroke with much less hardware. Use fishing line for the string, making it easy to replace when broken.
scad mientist, Apr 28 2015

       // All told you are looking at well less than 1/2,000th the capacity of a rechargeable. //   

       Which is fine for many applications. Many measuring devices last for multiple years on a single battery depending on how often they are used. These might operate for a single use session on a single winding. A wind-up battery won't die of old age and start leaking. Of course many such devices use coin cell batteries. Also, it would be annoying to open the battery compartment every time to wind them. Maybe that's the reason for the smell key hole. Drill a matching hole through the case and inset the key without opening the battery compartment.
scad mientist, Apr 29 2015


back: main index

business  computer  culture  fashion  food  halfbakery  home  other  product  public  science  sport  vehicle