Dead 2010 Prius -- suggestions?

Usually I would assume they would check the 12v battery and the associated connections. (grounding wires, bolts tightened)
I wouldn't think they would pass up an opportunity to sell you a $300 12v battery.

Go to a car parts store or a Batteries Plus to get a second opinion about the health of your 12v battery.

 

Incompetency is everywhere.

Why don't you test the 12V battery yourself, esp if you have a DVM?

Take these 3 readings:
1) In the morning, take a reading at the terminals. DO NOT start/move the car. You want the battery to have sat for a few hours, so any excess charge to dissipate.
2) Put car IG-ON (Foot off brake, press Power button 2x).
3) IG-ON, turn on headlights (HIGH Beam), fan on high, defroster, radio, etc.

A very healthy/new 12V AGM battery will read just over/under 13V.
A healthy 12V AGM w/ a load should (condition #3) be above 12V.

 

DVM (Digital Volt Meter), just so there is no misunderstanding.
You probably have a friend who has one. Call around.

Or, maybe just get a new 12V AGM battery. Yours is at least 6years old; possibly 7 y/o if purchased in 2009. You will have to replace it sometime in the very near future, which could be now.

Pepboys is having a sale on the Bosch AGM battery that fits Prius. $158 + refundable core charge.
Bosch, 4year total warranty, non-prorated.
Toyota True Start, 7year warranty, pro-rated; from $200 if you can get the local dealer to price match other online Toyota dealer parts price.
Years 1-2 100% of parts, service and towing
Years 3-4 50% of Truestart MSRP*
Years 5-7 25% of Truestart MSRP*

Car Batteries | Pep Boys | Battery Installation | Car Service

 

Sears
$10, acceptable, and probably way better than the cheapest Horror Freight (Harbor Freight) throw away junk
Sears.com

HD says these two are available in store today:
$37, a good value. The other two tools are useful, if you own your home/condo, and like to tinker/DIY.
Klein Tools Electrical Test Kit-69149 - The Home Depot

$49. I like this b/c its auto ranging, which you are paying for the convenience; not needed, but really nice to have.
Klein Tools Auto-Ranging Digital Multi-Meter-MM400 - The Home Depot

OSH & Ace Hardwdare shows no DVMs.

Horror Freight, as a last resort.

I got Carson Toyota to come down in price considerably for my replacement 12V, 7-2014, $163.31 (before tax). Today, I would be fine buying a Bosch from PepBoys, esp if I could get it on sale.

 

open the hood, and take the cover off the fuse box. there is a red cover that swivels on a hinge on one side. flip that up and you have the 12v jump point. there is only metal on one side of the jump point, so you have to put the positive (red) cable on that side. put the negative on any close by unpainted bolt, stud or nut. there are drawings of the jump point in your owners manual.
check it after the car has been off for at least several hours.

 

There are probably YouTube videos of DVM.

For DC (Direct Current) measurements:
Red is supposed to be the HOT (positive).
Black lead is for ground (negative).
If you reverse the leads, the reading will just be negative instead of positive (-12 vs 12).

I believe Gen3 cars have the 12V battery in the engine compartment. The Red (positive) lead on the Positive terminal at the battery post (under a red cover). The Black lead (negative) on the negative battery post or a unpainted ground bolt somewhere nearby.

 

It's a six year old 12v, four years is good, five better, six....

At least charge it once a week, but it's time for a new one.

 

gen 3 still has the battery in back. but it is easier to open the hood, take the cover off the fuse box, then flip up the red cover over the 12v jump point.

 

Dial should be in the "7 o'clock," position, at the number "20".

Black test lead plugs into "COM" on the Klein DVM. COM, is an abbreviation for COMMON, aka GROUND.

Red test lead will plug into the right side of "COM". This right connector has the following symbols:

V = Voltage

Ω = Omega = Ohms (resistance)

and other symbols which Word does not seem to have.​

 

I think you should get the $10 Sears DVM. The $37 Klein set, has two additional tools you may never use.
I don't know how close a Sears is to you though.

Consider getting a 12V battery charger down the road. Perhaps a Xmas wish list for someone to get you.
$47 Schumacher

$80 CTEK

Both charger can do the 3 common battery types: wet, gel, AGM
Both fully automatic.
I went w/ the Schumacher b/c we still have conventional cars w/ larger batteries; I want that faster charge rate.
The Ctek is really nice. Especially the battery post attachment that can be attached and left behind.

Some view a battery charger as a waste. They just proactively change out the battery (every 4years). However, if you should ever leave a door ajar for a prolong period of time, or accidently leave any interior light on (map, dome, trunk), your battery might be drained enough to where it won't start the car. The charger will bring it back.

 

or amazon, they should have one.

 

Glad you got it fixed. I was going to guess the battery also before you posted the resolve above.
I now replace my 12v every 5 years no matter what the dealer says the of the condition following a test. My 12v died at the 6 year point and raised havoc with almost every system of the car. My fobs were also reporting low, despite having new batteries in them before my problems. New 12v fixed all of this.

 

I'd still look into multimeter and charger as mentioned above, digital load tester like Solar BA5 is good too. Really frees you up from having to rely on the professionals' honesty.