Where is large battery located in 2008 Prius?

The Toyota Prius Owner's Manual makes opening the rear door from the inside look easy. It's not a simple two step process see picture from your manual

Here's a step-by-step guide to open your Prius trunk (a.k.a Boot, a.k.a Rear Door) when your battery is dead. Step 1: Flip Down the Rear Seats Push the button next to the seat belts on both rear seats and pull down the seat backs. | Source To begin, you need access to your trunk from inside the car. Unless you are exceptionally small and Barbie doll thin, you will not fit through the narrow opening between the top of the rear seats and the inside of your roof. Of course, this is where small children can come in handy, but that's the subject for another article. Press down on the button, and pull down the seat backs for both rear seats. You can now go caving into your Prius trunk in search of the Holy Grail: The Door Lever. Step 2: Pull Back the Carpet to Expose the Tool Box Pull back the carpet to expose access to the tool box. | Source Hopefully you are one of those rare individuals that doesn't actually store anything in their car trunk. If you are not, step 1a is to empty your trunk. Once empty, you can pull back the carpet to expose the tool box. You are looking for the tiny fabric tab very near the rear door. Here's a zoomed in picture.... Step 3: Pull Back the Tool Box Lid You need to pull the tiny fabric tab near the rear door to open the tool box. | Source Pull on that fabric tab to open the tool box lid. It should open easily, but If the lid resists you, take a breath. It's not trying to add to your already bad day, it's just locked. To the left and right of the tab, respectively, are two locks. To unlock the tool box, the arrows on the locks should point to the side (left for the left side lock, right for the right side lock). If they point to your rear door, they are laughing at you and keeping your tool box lid locked. Turn the two tool box locks to 3 o'clock and 9 o'clock. If the arrow points at your closed trunk lid, your tool box lid is locked. | Source Step 4: Remove the Cover There is a plastic cover in the tool box lining that protects access to the trunk lever. Remove it. This picture is with cover removed. | Source We have now join the owner's manual already in progress...you can now remove the plastic cover. The tool box lining has a small plastic cover that protects access to The Door Lever. You can fairly easily pry it off. If it makes you feel better to express your increasing anger at this process, use a screwdriver and damn the owner's manual...pry that cover off and don't use a rag to protect it. It's a cheap piece of plastic whose sole purpose is to obscure access to the The Door Lever. Personally, I threw my cover out. It was gratifying, and it will never again block my access to The Door Lever. Step 5: Pull The Door Lever Pull that silver, backward c-shaped lever toward you. The trunk door will pop open. | Source This is where the owner's manual writers were seriously smoking something. The manual makes it appear that 1) this lever is easy to find and 2) you can pull it up. First of all, you are going to have to feel around for this lever. It's buried inside the rear door and, because you are already reaching through the tool box liner that is IN the body of your car, it is below your eye level. You head won't fit into the tool box to look the The Door Lever in the eye. Second, the owner's manual arrow is drawn incorrectly. You couldn't possible pull that lever up from the position in which you are contorted. It defies physics. Reach two fingers straight into the black abyss, once you feel this lever, pull it TOWARDS you. Voila! Trunk door pops open, you can push it up, and feel the freedom

Hmmm, did I miss something? The question asker just wanted to know where the big battery was.....