A high-rate discharge test should use a load that is _______ the CCA rating of the battery.

• A. 1/4
• B. 1/2
• C. 3/4
• D. 1

Answer: (B)

The test checks how a battery behaves when it is asked to deliver a heavy current. CCA is the maximum current the battery can supply for a short time under cold conditions, so a high-rate discharge test wants a load that pushes the battery, but not to its absolute limit. Using a load around one-half of the CCA rating provides a meaningful stress: it’s strong enough to reveal weaknesses such as high internal resistance or poor voltage under load, yet it’s not so extreme that the test becomes unsafe, impractical, or risks rapid, excessive discharge. If the load were much smaller, the test might not show how the battery performs under real high-drain conditions; if it were full CCA, the test could be unsafe and harder to manage, and it could wear the battery more than necessary for diagnostic purposes.