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I was wondering what the arguments would be besides the chance of explosions, or mishaps when a potential spark could ignite volatile gases. I already know of that potential liability so I don't need any clarification on that topic.

But someone else on a different, but similar question on StackExchange stated that:

"...the return current does not have to travel through the dead battery's minus terminal hookup cable and then to the jumper cable, but can go directly from the chassis ground to the jumper cable."

"A more direct return path allows for better current flow and less voltage drop, like plugging a big appliance directly into an outlet, rather than via an extension cord."

But what does that even mean? Hooking up the negative jumper cable to the negative terminal on the dead battery makes more sense instead of the ground because the clamps would be directly on the dead battery terminal. Wouldn't that be a more direct return path versus grounding it to the vehicle chassis?

Edit #1

This is not a duplicate of another question. This question is asking why is the ground used instead of the negative battery terminal when jumping a car. The previous question is asking why do negative cables NOT SPARK/ARC when disconnecting/reconnecting. I'm guessing nobody is even reading questions anymore.

marked as duplicate by Zshoulders, cory, Pᴀᴜʟsᴛᴇʀ2 Feb 10 '17 at 21:53

This question has been asked before and already has an answer. If those answers do not fully address your question, please ask a new question.

migrated from electronics.stackexchange.com Feb 10 '17 at 19:07

This question came from our site for electronics and electrical engineering professionals, students, and enthusiasts.

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    Reducing the chance of explosions is a pretty important reason; why do you need any other? – Dave Tweed Feb 10 '17 at 17:15
  • A link to that other page is necessary I suspect. – Andy aka Feb 10 '17 at 17:18
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    Anyway, the point of jumpering two cars together is to charge the battery, not start the car. The fact that the car providing the boost can charge the dead battery even a little bit is what allows the other car to be started. – Dave Tweed Feb 10 '17 at 17:18
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    electronics.stackexchange.com/questions/74956/… – Andy aka Feb 10 '17 at 17:26
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    I have downvoted your question because you specifically say you don't want to hear the correct answer. We place a negative cable to the ground instead of the negative terminal to prevent an explosion. – TecBrat Feb 10 '17 at 19:49
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Avoiding sparks near the battery is the main reason for the common advice to make the last connection to ground away from the battery on the vehicle with the dead battery. It is best to make this connection directly to the engine or to some sturdy metal part bolted to the engine. The reason for this is because the starter is mounted on the engine and the starter current return path is through the engine. Making the connection elsewhere on the chassis can reduce the voltage available at the starter because the high starting current then has to flow through the engine-to-chassis ground connection, which might not be sized to handle the current, or especially on older vehicles, might be corroded or otherwise defective.

From a purely electrical point of view, the difference between connecting directly to the engine or to the negative battery terminal, which is connected to the engine by a few feet of rather large cable, is negligible.

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