# Car battery recently replaced - could it cause static buildup?

I recently had my car battery replaced. Ever since then, the first person to get out of the car gets a static shock. This never happenned before. Could it be that the new battery is set up in such a way that it is contributing to charge buildup in the frame?

Now, I dont know if this is relevant, but to test my theory about this, I did the following: I took the jumper cables and connected the red to the positive terminal, the black to an exposed metal part of the car and touched both ends together. It sparked. Doesn't that mean there's charge buildup in the frame?

• No, the negative battery cable runs to the car body. With your jumper cables you're completing a circuit.
– Ben
Commented Feb 21, 2017 at 22:10
• @Ben - Why not just answer the question :o) Commented Feb 21, 2017 at 22:58
• @Pᴀᴜʟsᴛᴇʀ2 My comment doesn't really address OPs question. Just wanted to clear up the jumper cable test
– Ben
Commented Feb 21, 2017 at 23:05
• Have the tires recently been replaced? Commented Feb 21, 2017 at 23:16
• Did the change in battery also happen to occur during a change in weather from warm and humid to cold and dry?
– cory
Commented Feb 22, 2017 at 13:57

## 3 Answers

The usual cause of static shock is not the car's body (which is grounded through the tires). When you get out of a car, the friction of your clothes on the seat causes YOU to become statically charged. The shock comes when you discharge yourself through the car body (usually the door frame).

This effect is more pronounced when humidity is low (e.g. in winter, when it's freezing). A static charge can be thousands of volts, which is why the shock is noticeable - you actually draw a spark when you approach the car body to within a few mm.

The battery can't possibly charge the car body to more than 12V, and 12V happens only if you connect the battery the wrong way round, i.e. connect the positive terminal to the car body instead of the negative terminal.

To test what causes the problem: use a multimeter to measure the voltage between the car body and yourself. If the multimeter indicates a constant voltage, the battery is the problem. If you get an initial peak that quickly drops to 0, it's a static charge.

People getting static depends on several factors which include, but are not limited to, the material of the clothes they are wearing, what shoes, the material on the car seats, did they touch the metalwork of the car on exiting and the humidity in the atmosphere - static is much more noticeable when the atmosphere is dry. Changing the battery is a very unlikely cause.

What the other answers failed to mention is that static electricity shocks have a very high voltage measured in thousands of volts. The 12V voltage of a car battery is way too small to cause any buildup of static electricity.

The high voltage of static electricity shocks is so high that if the voltage was continuous, it the current would kill you. The reason static electricity shocks don't kill you is that there is a limited amount of charge, and when the charge is depleted, the current flow stops.

So, the answer to your question is that your car battery has absolutely no possibility of causing static electricity shocks. To verify this is true, do this simple experiment: touch the negative terminal with your left hand and the positive terminal with your right hand. Do you feel a static electricity shock? If not, there is no way the origin of the static electricity could be the battery.

Edit: I should mention that in theory somebody could build a device that up-converts the low voltage of car battery to a voltage high enough to cause static electricity shocks. So, in theory, with a suitable device you could use the low 12V voltage of a car battery to create static electricity. Does your car have such a device? Probably not, unless you have added such a device to your car.

• At least one of the other answers didn't fail to mention this... Commented Feb 22, 2017 at 14:49
• Ah, yes, you're right. I should have read your answer more carefully. You got yourself an upvote! Commented Feb 22, 2017 at 17:18