Battery efficiency and internal energy

  • Thread starter spyboy
  • Start date
  • #1
1
0

Homework Statement


One rechargeable battery of mass 15.0 g delivers to a CD player an average current of 15.5 mA at 1.00 V for 2.50 hr before the battery needs to be recharged. The recharger maintains a potential difference of 2.00 V across the battery and delivers a charging current of 10.0 mA for 4.90 hr.
a.) What is the efficiency of the battery as an energy storage device? There will be no units for efficiency. (Hint: Efficiency is the ratio of energy used by the CD player to the energy delivered by the charger.)
b.) How much internal energy is produced in the battery during one charge-discharge cycle?

Homework Equations


E=I*V*t
Efficiency = Eout/Ein

The Attempt at a Solution


I got part a easily enough (.395), but part b has me stumped. Initially, I thought that internal energy loss would be the difference between Eout and Ein (Ein-Eout). Eout I got to be .03875 J, and Ein is .098 J. The difference between them is .05925, but this isn't the correct answer. Any suggestions?
 

Answers and Replies

Related Threads on Battery efficiency and internal energy

Replies
14
Views
1K
  • Last Post
Replies
8
Views
4K
Replies
2
Views
5K
  • Last Post
Replies
1
Views
9K
  • Last Post
Replies
10
Views
3K
  • Last Post
Replies
3
Views
4K
Replies
11
Views
11K
  • Last Post
Replies
8
Views
9K
Replies
0
Views
4K
  • Last Post
Replies
3
Views
1K
Top