Prius 2009 it start ready for just 2 or 3 second

You will need to post the OBD2 codes here for additional help.

If you have a OBD2 bluetooth adapter and a phone or tablet (either will need bluetooth), you could use an App like Dr Prius or Hybrid Assistant to retrieve the OBD2 codes (DTCs).

 

Usually its the 12 volt battery in the hatch. In the night without starting the car turn on the headlights. They should be very bright.

The best way to test the 12 volt is to get a dc voltmeter and test the front under hood jump point. It is under the little black plastic fuse box on the right under the hood. In that box is a little red plastic cap and under that red cap is the 12 volt battery jump point. measure there. Do not measure at the 12 volt battery itself. It only matters what voltage is actually feeding the fuse box.

it is in the owners manual.

With car off should be at least 12.3 volts. With car off turn on the headlights and measure the voltage at that jump point again. If it dips below the 12.3 usually means the battery cannot even provide juice at with a minor load and should be replaced.

If you ever had to jump start the car that battery is toast.

If battery tests ok it may be bigger issues and you have to do like SFO recommends above. if car will not start it will launch codes (lights
on the dash) that will tell you why its unhappy.

get the codes and post them back here.

 

At this point the hybrid battery may be too low to turn over the gas engine any more.

Usually you only get 5 it so attempts before state of charge drops below ~40% and car can't start.

At that point you will need to buy/build a high voltage charger to charge up the batttery, or takes the car to a shop and pay to have it charged.

If you can share the error codes, or view liv data like high voltage battery state of charge, it will help give better insight into the root cause of the problem.

 

What in it starts? If the engine seems to starts and then shuts down it's actually not starting and is draining the hybrid battery. Stop doing that as the hybrid battery will fail eventually!

Put the Prius in ign-on by pressing the power button two times without pressing brake pedal. How many bars does hybrid battery have on mfd? Less than 2?

Check the 12V battery voltage you can do that even without the volt meter: Toyota Prius: How to Check the 12v Auxiliary Battery Health - PriusDIY.com just do the Test 1. in step 5. then just power off. If that's bad you may need a new 12V battery or just charge it.

If the 12V battery has enough voltage you will just need to read the fault codes. Codes are read in ign-on that you get by pressing the power button two times without pressing brake pedal. You will need a scan tool to read the codes best would be to use Techstream. Cheap way to get it is Mini-VCI. Then you could use it to read the codes and all freeze frame data. If you can post all that here we can surely help.