2005 Prius will not start after replacing 12 volt battery

First off thanks for the replies. Yep! everything worked prior to the battery dying.
Checked the connections and they're solid and tight. neg terminal sparked at contact. All I have is the red key light flashing. Found a youtube video where a right hand drive (mine is a left hand drive, north American car) used his existing key and the following sequence but it didn't work. Anyone have a procedure as I don't have a tool to connect to the car to program it?

Sequence I followed (that didn't work)

1. Start with the door open.
2. insert and remove key twice
3. close door
4. open and close door twice
5. insert and remove key once
6. open and close door once
7. insert key
8. push power button twice
9. remove key

and it was supposed to beep and then the ignition should have worked. But failed.

 

First off thanks for the reply. I tried your suggestion and still have no ignition or power to the dash other than the flashing red key light and if the door is open the open door indicator. Found a youtube video where a right hand drive (mine is a left hand drive, north American car) used his existing key and the following sequence but it didn't work. Anyone have a procedure as I don't have a tool to connect to the car to program it?

Sequence I followed (that didn't work)

1. Start with the door open.
2. insert and remove key twice
3. close door
4. open and close door twice
5. insert and remove key once
6. open and close door once
7. insert key
8. push power button twice
9. remove key

and it was supposed to beep and then the ignition should have worked. But failed.

 

What's the voltage of your 12v? Did you disconnect anything else prior?

 

Stop with the sparks unbolting the negative lead. Both power leads from the battery the big cable which is the main 12 to the front fuse box jump points and the little cable which is the 12 volt sense lead to the inverter terminate to white plugs on the assy that's bolted to the 12 volt post. Squeeze those white clips leads together and unplug. Then the 12 volt is disconnected from the body no sparks. No sparks that why Toyota made it this way. The Toyota Prius does not Like sparks on its main 12 volt buss for the 12,000 time.

 

My car Prius 2009 start on ready for just 3 or 4 seconds with (ABS, VSC, and break)
then after few seconds (3 or 4 seconds), after that a red triangle with a sound has been appears on the dash screen,then the system immediately power off.

 

test the 12v. if thats not it, put a scanner on her