Weird sequence of events

Don't bother having it tested just replace it. A dead 12 volt battery is very bad in a Prius because it exposes you to a jump start and so many
Prius's have been damaged by idiots reverse polarity the jump leads. $$$$$$ of damage. Especially AAA jump starts. Do all you can to not get a dead 12 volt battery.
12 volt jump start gone bad is really common here.

So many dealers are unable to properly test a 12 volt battery.

Best defense against against a dead 12 is to arm the alarm every single time you get out of the car especially in the garage as that will alert you to a door open which leaves the light on. And to maintenance charge it once a month using the front underhood jump points. That will give you alot of insight into the battery health as you can track how quickly it charges up and if it takes a full charge to 0 current draw.
Very noticeable when it starts to go south on a charge routine. On a normal car you will hear the battery struggle to turn the starter. On a Prius all the on button is doing is closing alot of relays so you have no visible indication the battery is going bad. It will leave you at the worst time.

Btw, your posting in the wrong forum. This should be in the Maintenance & Troubleshooting section.
You'll get a better response in that forum.

 

Good...you'll get a better response in the Maintenance section. Yeah don't mess with the 12. You can either get a dealer oem unit about $350 installed (price varies) or a Optima Yellowtop from Autozone buy it online pick it up locally for about $160 with $50 coupon and diy.

I have a yellowtop it fits perfectly no change of posts. Plops right in. Been pretty good for 2 years so far. I charge it about once a month just to see how its doing. if your thinking of dyi post back and I can give you some tips on the r & r.

And you can't delete a post. What you can do is hit the EDIT button on the bottom of your post and delete your post and replace it with just a period . as it requires some input on the page. Can't leave it blank.
So your post will just have a . in it. Which is ok we see that alot and have done it myself.