6

Safety. Connecting the second cable makes a spark. You want it away from the battery. A depleted and over-discharged battery may outgas hydrogen. Hydrogen is explosive. Lower resistance (not much, but still) - when starting, the current flows in general from the running alternator of the working car to the starter of the dead car. An exposed metallic part of ...


5

Car batteries are extremely well-connected to chassis Almost all cars use the chassis of the car as the (negative) ground. Chassis is extremely well bonded to the battery negative terminal, since this is the normal current return path for the starter, which can pull up to 1000 amps. So no, there will be as little resistance as you can find. Your biggest ...


5

In theory it will work. In practice, it will also work. Yes there is extra resistance as you have increased the path to ground. In a perfect system each ground would be equal, but it is not a perfect system. Due to the large surface area it is minimal but there will be some resistance. And due to the large current needed in charging and turning over a motor, ...


3

When a Battery is disconnected from a running engine, there is a milliseconds high voltage spike that occurs the instant the terminal leaves the battery connector. Some researchers say it can be as much as 150v in your vehicles 12v circuitry. Remember that ECU operating voltage is 5v. A customer brought a car to me with all the lamps blown. I asked him what ...


2

The current path of interest is the battery to the starter motor on the car being started. Each battery has a cable running from the negative terminal to the engine block or transmission near the starter motor. If you attach the cable to the engine block on the non-running car you can bypass one of the cables (which can only be better). I usually attach ...


1

The very first thing to do with this is get your battery checked. Then if bad, replace it. Then when you have a working battery, check the charging system. Make sure all battery and charging system cables are cleaned and not defective. This can not be diagnosed until these steps are taken and done properly. It may even solve the problems.


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