VERY dangerous because the battery isn’t bolted down. Any speed bump, fast stop, or wide turn and the battery is going to move, sway, or touch against something it shouldn’t and spark. That spark could potentially cause a fire; the battery could also hit the hood when you hit a bump and spark.

A typical car battery weighs approximately 35 lbs. Imagine the damage a rolling 35 lb object can do to your engine compartment… when it gets launched due to a sudden evasive maneuver to avoid an idiot on the road.

If you hit a bump, the battery can bounce and when that happens, the plates inside can crack. If a broken piece of plate is flopping around, it will short out the battery so it drains when parked.

It might not happen on every bump, but it only needs to happen once.

Yeah its pretty dangerous. When I was younger and quite a lot dumber I had a Foxbody mustang gt. When I would kick the rear end out or take a hard turn sometimes itd just shut off like a light. I checked so much shit before it dawned on me there was nothing holding my battery in place. I’m lucky I didn’t set that pile of crap on fire lol, let alone crash when my car turned off with the ass kicked out.

Not good. The battery can flip over spilling acid or breaking things or the battery (+) post can touch metal parts and arc causing a fire.

Tie it down with bungee cords or rope before you drive.

This brings back memories.

My father supplied me with my first car in 1979 - a 1966 Ford Fairlane with a 289 c.i. V8 2-bbl. The thing was so freaking heavy for a midsized car, but it could smoke the RR tire on a right turn.

Dad maintained the cars on-the-cheap. He replaced the battery and mentioned it in an off-hand way when I was about to leave for my part-time job. “Go easy, lad - the battery’s not quite secure” (lad - he was an English transplant in New Jersey).

As I sped into the work parking lot, there was a bang, squealing sound, and more noise. And steam. The battery slid into the radiator fan, and the blades cut the battery open, spraying sulphuric acid all over the engine compartment. I called home - dad brought a fresh battery and swapped it in right in the parking lot. This time, he tied it down with a coat hanger.

The paint under the hood didn’t last much longer after that.

Every now and then, I’ll catch the smell of Sulphur in diesel fumes and it takes me right back.

My battery fell out of place once. I didn’t have the right fasteners. It fell over, shorted everything, turned off my power steering, while I was rolling downhill on a road by the coast. It was sparking bad and even melted my engine cover a bit

Realistically. It doesn’t matter… You’re battery will not jump out of your hood and dance around.

Have you ever heard of any type of incident from a loose car battery? The only way it could cause any type of damage is if you were in a roll over and the battery was laying on one solid piece of metal.

So what’s the year make and model of the vehicle in question?

Yes it’s dangerous but if you give us that information we can point you to an exact fit replacement

VERY dangerous because the battery isn’t bolted down. Any speed bump, fast stop, or wide turn and the battery is going to move, sway, or touch against something it shouldn’t and spark. That spark could potentially cause a fire; the battery could also hit the hood when you hit a bump and spark.

A bungie cord would be a cheap band aid. But if you’re in a high speed accident, that thing will fly out and kill somebody. Get it fixed asap

It might be a bit dangerous, depending on how far the battery can move. On many cars, there’s a other things in the way that will stop it from getting very far. However, it isn’t good for the battery to be rattling around, and if it pulls on the battery cables and that causes connection issues all sorts of weird stuff will start to happen, possibly at a very inconvenient time.