The hybrid batt (high voltage) only drives the electric traction motor (also used to start engine) and a/c, the rest is operated by the 12V battery (meaning the ECU which runs everything), so if this batt is dead there is no start to the vehicle.

If its 3-4 yrs old its probably going bad/or has bad cells. You can jump it (or try charging it with a battery charger of your choice) and try to make it to an autozone or like place for further testing. If you have a voltage tester check it, s/b at least 12.6, otherwise go get another one. Luck.

 

Ok, you have 2 batteries.
1. traction, aka hybrid battery. You should be able to see its state of charge on the display. Anything above the bottom 2 marks is Ok.
2. 12V battery. Presuming, that is the one you charged off the truck.
Start with replacing 12V.

12v ALTERNATIVE

Credit goes to a CD poster howardc64 Looks like group 24 batteries are a perfect fit. Got one from Pep Boys (Bosch AGM 24) that measured 10" x 6.5" x 8" so identical to the Panasonic. The +- posts are in the exact same location as the Panasonic (group 24F (I guess F=flipped?) has the +-...

www.toyotanation.com

Read through the last about 2 pages, for the latest on batteries.

 

it needs a load test.. take it to a shop that sells and installs AGM 12v car batteries (not many have the particular 12v agm battery you will need in stock, but they can get usually them), ask them to do tests to see if has issues taking and keeping a charge. Get a smart charger that charges your battery at home, often they have an AGM mode. I also have a jump starter I keep charged and ready to use, just in case (Gooloo).

 

So I wasn't sure if the alternator is turning and charging the battery.

There is no alternator.