water-powered clocks and calculators

Re those clocks and calculators powered by a water battery, e.g.:

http://www.thinkgeek.com/gadgets/electronic/757e/

Can someone tell me how to make such a battery? One that would fit into
a relatively small space such as the commercial products do? Or is it
possible to purchase just the battery somewhere?

 

The only way to purchase this "battery" is to buy their bill of goods.

It operates on phlogiston. It's got a moisture sensor, a CMOS comparator,
and a watch battery.

Sorry,
Rich

 

A watch battery?! Sounds like false avertising.

 

There actually is a water-powered "battery" I read about maybe a
year ago. Water is forced under pressure (maybe gravity alone?)
through a slightly porous ceramic element, producing a voltage
difference across the ceramic. I don't recall OTOH what physical
principle was involved. I think this is a really low current device,
but might be fine for CMOS clocks.

Best regards,


Bob Masta
dqatechATdaqartaDOTcom

D A Q A R T A
Data AcQuisition And Real-Time Analysis
www.daqarta.com
Home of DaqGen, the FREEWARE signal generator

 

You can make a battery using salt water and copper and aluminum,
but you need 5 cells in series for 1.5 volts to power a clock.

Here's an example:

http://ourworld.compuserve.com/homepages/Bill_Bowden/page13.htm#salt_w.gif

-Bill