In a moderately severe collision impacting a car hood (say, 40 mph,) which components are likely to get mangled first?
Is the car battery likely to leak acid?
depending on where it is, yes, it’s just a plastic case.
It’s absolutely possible but during my time in a body shop it was actually more rare than you’d think. A lot depends on the battery location. Some are behind the engine, some are in the trunk and some are beside the engine toward the front, which would be the most likely to be damaged and leak. But, depending on the car, a light hit on the right place could do it.
You also asked which components are likely to get mangled first. Radiators would probably be the next most common large engine component to be damaged.
OK. My car got smashed from the right (passenger) side, around the hood area.
Did you look?
Not a collision, but I have a funny battery acid story.
An acquaintance of mine in college was a borderline bad driver with a poorly maintained car, but it was one of the few cars in our circle of students. He also drove…enthusiastically.
For some reason, his car’s battery wasn’t secured. It sat on a shelf-like rest in the engine compartment, but was not tied down or bolted in place. Did I mention he drove enthusiastically? From time to time, he’d maneuver too fast, there would be a “clunk,” and he’d pull over, open the hood, and lift the battery back up onto its rest. This became routine for him, despite several of us urging him to seek some mechanical solution.
One rainy day, he was going to the bus station, and generously offered two of us a ride. Halfway there, he yanks the wheel too hard making a turn, we hear the now-familiar clunk, and the car goes dead this time.
We get out in the pouring rain. He pops the hood, and we can see the battery has fallen down farther than usual and become wedged. So he rolls up his sleeves, reaches in, and begins tugging on the battery. After a few moments, however, he swears and leaps back, shaking his hands. He looks around wildly, spots a muddy roadside puddle, runs over and bends down to stick his palms flat in the puddle. Battery acid! It must be cracked and leaking.
So the OTHER GUY now reaches in and grasps the battery. Seconds later, he too is sharing the puddle, cursing. From their bent-over position, they look up at me and ask, “Aren’t you going to try?”
As much as I appreciated the ride, I decided the puddle wasn’t big enough for three people.
And they graduated high school???
And how the hell are we supposed to know where the battery is in YOUR car? You haven’t even said what kind of car it is (year, make, and model).
[lighthearted name-calling expletive left out, but it was hard] 
The obvious lesson being, if you’re going to take corners vigorously in the rain with an unsecured battery, pick a route with bigger puddles. Sheesh! Anyone should know that!
he’s lucky the battery terminals never shorted to the body or other part of the car; lead acid batteries can dump almost a thousand amps into a dead short and hot melting metal can easily set a car on fire.
how can you ask that when we’ve actually had people here respond “how does it matter what kind of car I have?”
Wait a minute – are you intimating that not every car is engineered to be exactly the same in all of its mechanical particulars? Oh my.
Sorry, 2009 Smart Car. The right side is where the battery is.
What model of Smart Car? Some Smart Cars have the battery under the passenger floorboard. If it’s a hybrid, don’t touch it. If it’s a regular gas car there’s no way to know if it leaked without looking at the battery. I’ve seen massive impacts where the battery was knocked back a foot but didn’t leak and I’ve seen fender benders that obliterated the battery.
What exactly are you worried about? If it’s at the shop getting fixed, it’s their problem. If it’s in the driveway and won’t start, it could be anything. If you are worried about acid and the battery is under the hood, dump a box of baking soda on and around the battery and wash it off in a day or two. If you’re trying to replace a leaky battery, get some gloves and take the battery out and put it in a bucket with baking soda in it and take it to a recycling center.
It’s a regular. I think it’s the floorboard.