Problem. Car is dead, jump start did not help.

OK, maybe a bit of overkill in the cartoon, but I find it amusing!
Anyway, yes, you are going to need a new 12 volt battery. A yellowtop optima would be best, there is now a model for Prius, no adapters needed ... Optima DS46B24R Optima battery $175 direct fit replacement for Prius 2004 + & Plug-in Prius with Instructions Once you get that in, you should be fine. Unless you inadvertently reversed polarity on your jump attempt. That could be costly. But one step at a time, battery first!
Keep us posted on what happens next!

 

Here in SoCal got the Optima battery at Autozone but may be cheaper ordering from Amazon. Youtube is helpful to take a look at this particular battery. When my '07 Prius batt went out in the adjacent parking lot, a nice employee at Autozone had helped jumpstart my battery. They also said they knew someone who could put it in for $25, but ended up putting it in ourselves. I am currently looking at the portable Energizer Jump Start system 400 which has an inverter dock on the back.

 

Look closely at your jumper cable clips. Chances are, only one jaw is attached to the cable. You need to make sure that jaw is on the metal side of the under hood jumping terminal.

 

Very good point, without a good ground, you can jump till yer blue in the face, it's not gonna work!

 

I'm not talking about the ground. The jump terminal in the Prius is a peculiar plastic/metal thing. Only one surface of it is conductive. Some cable clips only conduct to one jaw at each end. If the conductive cable jaw mates with the plastic side of the terminal nothing happens.

 

You might want to consider reviewing this thread when thinking about replacement 12V batteries.
Fitting mobility 12volt AGM battery. | PriusChat

 

The product is probably a much smaller AGM battery that's packaged in a pretty box with its own charging circuitry. It will age at a similar rate to your battery and be an extra 20 lbs that you lug around everywhere you go.
Probably easier and cheaper to just plan on replacing your battery based on its age before it fails next time.

 

Sorry to hear of your misfortune C, hope it gets resolved soon.

 

With jumper cables connected correctly, the hatch should open normaly. The lights should work but you may have to make the car ready then turn off then make the car ready again. This proceedure will be rquired when fitting a new battery.

John (Britprius)

 

Use the dome light as your indicator while trying the cable clamp in different positions. Also try using different cables, if possible. I know of no issues getting power to the battery from the underhood terminal other than what I described above.

There's an access to the hatch latch release from inside the cargo area if you want to get to the battery directly.

 

If you are certain you connected the cables correctly, and at no point reversed them something other than the battery is wrong. If you have a voltmeter or can borrow one check for 12 volts at the jump terminal, also just below the jump terminal there is a clear plastic cover over a long metal strip is that strip intact.

John (Britprius)

 

It is possible the ground cable from the 12 volt battery has a bad or corroded connection where it fastens to the bodywork. This happened to a poster earlyer on this week, but I do not think this is your problem.

You do not need to run the car jump starting you, the Prius only needs a small current to make it ready.

John (Britprius)