EVITP EV Technology Fundamentals 4

Question 1

An EVSE sends a J1772 control pilot signal with a 40% duty cycle. What maximum current is it advertising?

Accepted Answer

24 A

Answer

For duty cycles from 10% to 85%, available current = duty cycle × 0.6, so 40 × 0.6 = 24 A.

Question 2

What is the main purpose of the proximity detection circuit in a J1772 connector?

Accepted Answer

To detect that the connector is inserted and help prevent driving away while plugged in

Answer

The proximity pin tells the vehicle a connector is present and lets it detect the latch release, which inhibits drive-away.

Question 3

The North American Charging Standard (NACS) connector has been standardized by SAE as which document?

Accepted Answer

SAE J3400

Answer

SAE published the NACS connector as SAE J3400.

Question 4

How does the CCS1 (Combined Charging System) connector differ from a standard J1772 connector?

Accepted Answer

It adds two large DC pins below the J1772 layout

Answer

CCS1 keeps the J1772 AC inlet and adds two DC power pins below it for fast charging.

Question 5

Which is a key advantage of lithium iron phosphate (LFP) battery chemistry compared with NMC chemistry?

Accepted Answer

Better thermal stability and longer cycle life

Answer

LFP is more thermally stable and lasts more cycles, though it stores less energy per kilogram than NMC.

(EVITP) Electric Vehicle Infrastructure Program Practice Test