Shum make sure you have the following to teach this lesson
Large Cu and Zn plate with table salt, water and cloth.
Sack of potatoes, Cu, Zn plates, LED containers,
Lots of jumper wires
Galvani vs Volta
How Batteries Work
Electromotive Force … the force which produces, or tends to produce, electricity, or an electric current; sometimes used to express the degree of electrification as equivalent to potential, or more properly difference of potential. This end has more conductance This side has some conductance, but not as much as the opposite end.
Types of Batteries
Primary: One time use (disposable)
NiCad: Nickel Cadmium (Early as 1899)
NiMH: Nickel Metal Hydride
Lithium ion: currently most popular, High energy, popular in Laptops, iPods, PDA’s (some cases of exploding, only last a few years)
Lead Acid (wet cell) High Amps!! Heavy!
Basic NiCad Cell= 1.25 V @ 500 mAH
Can produce 500 ma for one hour
10 mA for 50 hours
1000 mA for 30 minutes (might get warm)
Batteries & Environmental Issues
Americans use an average of 5 cordless products per day (RBRC 2004).
In 2005 200 million cell phones were used in the U.S. with 130 million cell phones discarded annually (eartheasy 2004).
Disposal of cell phone batteries
Landfills: Leakage from single cell phone battery can pollute up to 158,000 gal of water
Incinerators: If burned release toxic dioxins and furan into atmosphere.