freeradical wrote:
[quote=Cary]
[quote=Bernie]
I would try an AA 1.5 volt over the 400 amp car battery.
Even an A/C wall socket will shake you loose but a D/C Car battery is not something I would do with a FAULTY meter.
:oldfogey:
I don't really understand this statement. An AC line voltage wall socket has the potential to kill you.
A 12v DC car battery? You can grab the leads with your bare hands standing in a puddle of water, and nothing will happen.
If you're talking about high voltage EV or hybrid batteries, or the ignition coil output, that's a different story.
Automobile batteries can provide lots of current. I knew a guy who was installing a second battery in parallel in is his VW Bug who failed to take his wedding band off. His wrench touched ground, and the inner surface of his wedding band was momentarily molten metal. He got lucky and got to keep the finger.
I used to work on comm systems with 48 volt station battery. The 4 rectifiers in parallel could supply 800 amps continuously, and 1200 amps momentarily. The cables that ran to the batteries were as big around as your wrist. A guy I worked with accidentally touched ground with a very large screwdriver (the shaft was at least as big as your pinkie finger) that was touching -48 volts. The screwdriver
exploded, and the room went white with the flash. Luckily, nobody was injured or died.
Sure, if you have a dead short across the car battery, bad things happen. Using the car battery as a test load for a DVM is not in that category.
If car batteries were that dangerous, the millions installed in cars would have much more insulation (a la hybrid battery packs with multiple safety interrupts and requirements for specific gloves and equipment) installed. Most cars have batteries with both terminals exposed.
You have to work really hard to have problems with a car battery.