iPad Battery

A battery is a container consisting of one or more cells carrying an electric charge and used as a source of power.

The standard rechargeable iPad battery is composed of lithium polymer. Engineers prefer this material because of its reliability, ruggedness, and lower cost of manufacturing. Other uses for lithium polymer include radio control equipment and electric vehicles. It is rated at 5.1 Volts and is capable of 9 to 10 hours of life depending on its usage.

This battery is an ion, more specifically an anion. (negative charge) It belongs in the lower part of the activation series. It will likely receive electrons from a more positive substance.

The innovators at Apple are constantly aiming to improve battery life and reduce its size and recharge time.

http://www.channelinsider.com/c/a/Tech-Analysis/Apple-iPad-Scores-High-Marks-for-Battery-Life-201796/

http://www.lunacommerce.com/679-ipad-battery.html



As the battery technology has improved, the voltage (from IG to 3G) has improved to 3.75 Volts to 5.1 Volts while being virtually the same size. This has increased the battery life by several hours.

In this scenario, the cord of the charger provides the charge, the outlet acts as the voltage source, and the iPad battery is the resistor because it transforms electric potential energy.



In class we discussed that voltage is the electric potential of an object, a field surrounding charged objects.

Lithium polymer battery

A Lithium-Ion Polymer Battery used to power a mobile phone
specific energy	130–200W·h/kg[citation needed]
energy density	300 W·h/L[citation needed]
specific power	up to 7.5kW/kg[citation needed]
Charge/discharge efficiency	99.8%[citation needed]
Energy/consumer-price	1.5-1.7US$/A·h[1] (2.2-2.5 W·h/US$)
Self-discharge rate	5%/month[citation needed]
Time durability	24–36 months
Cycle durability	>1000cycles[clarification needed]
Nominal cell voltage	3.7 V

Martin Reynolds, a Gartner analyst explains that,"the iPad's relatively large battery can dissipate heat better than smaller batteries. This allows Apple to use a processor that generates more heat and runs faster without causing battery overheating -- a problem when a smaller battery takes up a confined space." 

The articles describe that due to these advancements, iPads are steadily becoming more useful and replacing laptops at a faster rate.

The use of the iPad example has helped me understand how the amount of voltage relates to real-world objects.