Car refuses to start with repeated clicking but can be jumped

Day 1: My 2013 Infiniti JX35 won’t start. When I press the ignition button, the car loses all electrical power and I can hear repeated clicks under the hood.

I installed a new battery, and it started up right away and drove fine.

Day 2: The problem came back. Here’s what I’ve done:

• Checked the voltage on the battery: 12.6
• Turned on accessories without starting the car: no problems
• Scanned for codes: no codes

Then I jump-started the car:

• Jump-start worked
• Checked the voltage on the (running car) battery: 14.2
• Disconnected the black terminal on the battery: car continued to run

When I turned the car off and removed the jumper cables, it wouldn’t start again.

Day 3:

I went out to the car to check on things, and it was still clicking from the night before.