What the insides of a Prius nickel–metal hydride battery looks like
This is an image of the Hybrid Battery pack from a 2001 Prius. It sits in the front for the rear trunk just behind the rear seat.
This is an image of a battery pack showing the side view and the modules. The pack is slanted and air flows into the battery pack from the bottom left and goes up in the spaces between the battery modules as the space under the pack decreases. The air is actually drawn out of the pack from the top right and on the top there is more space for the air to flow on the right. This arrange allows for fairly even distribution of air flow throughout the battery pack.
From this side view you can see the 38 battery modules in the pack.
Click on the image above to enlarge it.
This is a module from a 2001 to 2003. The top exploded off this battery and the top is ragged on the left side. The solid vertical lines mark the divisions between each cell. There are six cells.
This is the insides of one cell. Click on the image to get more detail.