The old batteries had a conductive rubber outer case. When I was in tech school the instructor said to never put a battery on the concrete. Always put it on a block of wood. The concrete would act as a ground and suck the electrons right out of the battery.

Newer batteries do not use a conductive outer case, so this does not apply.

These gentlemen would be amazed at the new battery technology. 12 volts! A battery that could be mounted upside down if need be.

Most vehicles that locate the battery to under the back seat or in the trunk do that mainly because there is no room under the hood. For sports cars, it improves the handling.

Toyota Prius has the 12 volt battery in the right rear. The high voltage battery is positioned lengthwise.

Some Buicks have the battery under the back seat. These have vent tubes to direct the fumes out of the battery, down through rubber grommets in the floor to be expelled outside.

Certain Chrysler products require removal of the left front tire to access the battery. There is an access panel on the inner fender that exposes the electron storage device.

[My mother had a 1956 Lincoln with the battery under the front passenger floorboard. - Dave]

The battery in my '74 Corvette was in the back behind the driver's seat and in a '09 Charger it was in the trunk next to the spare. They aren't always where you'd expect them.

Who made a Battery of comments here

Phaedrus' comment reminded me of an incident in the early 1970s. My first wife and I bought a new VW Bug and decided to drive from Tampa to Naples that evening.

About halfway, I said to my wife, "Do you smell something strange?" She did, and as we continued to drive, the smell got worse and worse.

Something was awry in the electrical system, and the battery, which was under the back seat, had boiled over.

Road trips today are luckily more auto-incident-free than in those days, Devil stay unsummoned.

Only 6V (3 cells visible). Was there another battery to give 12V?

[Cars didn't have 12V systems until the mid-1950s. - Dave]

It appears that the front seat has been raised to access the below the floorboards battery location. My 1936 Packard 120 was so equipped, making the cable length to the starting motor more practical —- an important consideration for a six volt battery.

A long time ago I owned a VW with the battery under the rear seat. Since then I've seen a classic Rolls-Royce with the battery in the trunk/boot.

That's definitely an old school battery, with a hard rubber case, poured tar top, exposed bus bars, and diagonally opposed terminals. At least it appears to be easier to carry than most, having inset hand holds molded into the ends of the case. Batteries have changed a lot.

That the battery is stored under the back seat makes jump starting as simple as disassembling the whole damn interior. Here I am acting as a background extra in the HBO miniseries "Mildred Pierce", swearing by Autolite spark plugs.

When even a lowly car battery was a streamlined Deco masterpiece.