Why does a lead acid battery spark when connecting to opposite terminals

[Edible Planet]

Sorry about the intrusion as I really don't belong here as I have absolutely no background in physics but I have a couple of questions regarding lead acid batteries that I have been unable to find answers to on the internet.

First question - why does a battery spark/arc when the negative is hooked directly up to the positive. I had thought that the electron imbalance on the cathode was seeking to balance out by "getting" to the anode and it seems that hooking up the cathode directly to the anode would most easily satisfy this imbalance.

Second question - When the anode is grounded to a vehicle chassis how do the electrons get from the cathode to the anode to balance the battery. Do they flow through the circuit, power the load and then return through the metal of the chassis? And if so how does the metal of the chassis not become polarized by the charge of the electrons as they move through it? Or are the electrons just moving through a field around the chassis to return to the anode. Very confusing! Can anyone give me a good explanation.

Thanks,

Scott

 

[Bloodthunder]

For your first question, the sparking only occurs just before the wire from one end is connected to the other. You are effectively creating a capacitor for a moment. During this, electrons from the anode tries to flow to the cathode and arcs through the air, so you'll have a very tiny lightning bolt.

 

[pallidin]

Sorry about the intrusion as I really don't belong here as I have absolutely no background in physics but I have a couple of questions...

Intrusion? Not at all!
This site is open to everyone on the planet regardless of educational background.
As long as one posts specific questions and follows forum guidlines all is good and beneficial to us all.

Please feel most welcome here at PF!

 

[pallidin]

Do they flow through the circuit, power the load and then return through the metal of the chassis? ?

Yes. The sheet metal car chassis is just "convenient", not meant to be "ideal" for current flow. One "could" put more efficient copper wires connecting everything, but there is no need for that in most cases, hence the sheet metal of the car chassis is used.

 

[pmacias]

The sparking that occurs when connecting opposite terminals of a lead acid battery is due to the flow of electricity between the positive and negative terminals. When a battery is hooked up in the correct orientation, the electrons flow from the negative terminal to the positive terminal, creating a circuit and powering any connected devices. However, when the terminals are connected in the opposite orientation, the electrons still want to flow from the negative to the positive terminal, but they are physically unable to do so. This creates a buildup of charge and potential energy, which can result in a spark when the two terminals are connected.

To answer your first question, the battery sparks because the electrons are trying to flow from the negative to the positive terminal, but are unable to do so due to the physical barrier of the battery. This buildup of charge and potential energy is released as a spark when the two terminals are connected.

As for your second question, when the anode is grounded to a vehicle chassis, the electrons still flow from the cathode to the anode, but they do so through the circuit and any connected devices. The metal chassis acts as a conductor, allowing the electrons to flow through it and complete the circuit. The metal of the chassis does not become polarized because the flow of electrons is balanced out by the flow of positive ions in the opposite direction.

I hope this explanation helps to clarify the concept of sparking in lead acid batteries. Please keep in mind that there are many factors that can affect the behavior of batteries, and the information provided here is a simplified explanation. If you have further questions, I would recommend consulting a professional in the field of battery technology for a more detailed and accurate explanation.