Question

What is a twenty-hour rate of a battery?

(a) The current which the battery can supply continuously for 30 seconds with minimum cell voltage 1.2 V

(b) Lasting power of a battery on a small load

(c) Time for which the battery can supply 25 A at 80℉ with minimum cell voltage 1.75 V

(d) Rate of current for 20 minutes with a minimum cell voltage of 1.5 V

This question was addressed to me in a job interview.

The query is from Storage Batteries in division Nonconventional Engines, Conventional Energy Sources & Cooling System of Automobile Engineering

Answer 1

The correct choice is (b) Lasting power of a battery on a small load

Easy explanation: A twenty-hour rate of a battery is the lasting power of a battery on a small load. During this test, the temperature should be about 80oF. This rating is important for powering accessories when the engine is not running.