2012 Prius No Power until dome light is turned on

Here are some voltage readings from my >2 year old Toyota True Start, 84 month warranty, p/n: 00544-21171-325 battery.
The battery had been replaced before I purchased the vehicle.
Voltage readings were taken with a Fluke 87III & verified with a Fluke 73III.

This afternoon I had been driving the Prius & got home ~6:30pm & locked the car.
About 8pm I unlocked the car, popped the hood & took some measurements.
12.96 12.97 12.98... after 5 minutes it was up to 13.11V

The above document from Toyota says "turn on the headlights for 20 to 30 seconds. This will remove the surface charge from the battery".

I turned the headlights on for 30 seconds then turned them off.

12.96 after the headlights were off for 1 minute.
13.00 after the headlights were off for 2 minutes.

That was the end of the test.

Recently I had the inverter replaced & in that thread
2010 Prius died - P0A94 - Inverter Failure - Replaced | PriusChat
on June 28, 2014 I wrote the following:
"I just checked the 12V battery after the vehicle has been sitting all night...
12.93V at the fuseblock terminal - measured with Fluke 87 III"

This reading was after the Prius had been unlocked in the AM & the door opened to pop the hood.

This Toyota battery is a true AGM battery which will read slightly higher voltage than an older style flooded lead acid battery.
All voltage readings were made from the fuseblock terminal to engine ground.

 

like brand new.