Why aren't AA batteries square?

there are two round corners :-)

Try it sober...easy-peasy!

Less pressure.

There are if you drop a spanner across the terminals. I saw one where the top of the battery landed twenty feet away.

Bill

a) I would have thought 12V isn't enough to give a decent shock. b) Car battery electrodes are usually marked + and -, not red and black and c) Why would the polarity matter?

Indeed!

The man was making a point that anyone but you can understand, not writing a technical manual.

In that case he should have avoided any technical details.

A car igniton coil and a ttembler works wonders.

On 09/23/2017 05:27 PM, Bill wrote: [snip]

Maybe they do it (use multiple batteries) because of the varying needs of equipment and it would cost more to design more multi-cell batteries.

I've heard that "flashlight" came from when the batteries had such low capacity that it was too expensive to leave it on more than a second or so at a time.

The greatest amount of water contained by the least amount of mud, makes the "lake" round.

I guess you haven't heard about what happened in Houston TX last month.

The clamps often have red and black on them so "Red is positive, Black is negative" describes the connection.

It might be connected through an (polarity sensitive) electronic device to produce higher voltage pulses.

Doesn't matter if you get it wrong on both ends. The jump leads aren't fussy.

Now that would be more interesting to watch.

Do you mean a trembler? I thought they're like fuses. Why would you want to switch it off?

I've never seen one that isn't. The connections to the car though are sometimes red and black, or if it's a Renault, brown. I've seen some cars where both wires are red, or one's red and one's brown. If it's an old Espace with the positive wire running over the cooling fan, then it's on fire after a clip comes off and it shorts to ground. It was quite funny when the AA guy asked me to reconnect the battery once he'd replaced the wire, then backed off several yards, as he was "scared of electricity".

You really don't get humour do you?

Something blew over somewhere, I thought that was some islands? Weather in another country doesn't really interest me.

When I were young some torches could be illuminated briefly by pressing a button as well as having a slider switch. I assumed this was so you could signal your mates by Morse code rather than to conserve battery energy.

The article in Wikipedia shows an early "electric device" which appears to have only a momentary on type switch.

The first "dust buster" type battery vacuum cleaner I bought had a similar type switch, as did the first cassette recorders. It appears that eventually the convenience of a proper switch is seen as more important than conserving energy.

Before that - camera flashes and lighthouses: