IanA's Z300S Barchetta Build - Page 15

Lucky@LeMans · #**281** 21st January 2021, 15:21

One of blokes I worked with a while back was into model quadcopters / drones. The battery in one of those was the size of a match box and he dropped a fully charged one onto the concrete floor. It must have shorted out internally because it burst into flames, burned ferociously for 10 minutes and the fumes were horrendous. The same battery technology is in an electric car but hundreds of times bigger !

IanA · #**282** 21st January 2021, 17:22

Wasn't the Czech (?) supercar that Hammond crashed an electric device- that burned rather well as I remember.

I've now sorted the electrics on mine- just got to get the trim panels back in now before refitting the driver's seat.

Mitchelkitman · #**283** 21st January 2021, 21:31

Tread with caution if planning to build an electric kit car - you have to know what's what ( I certainly don't) and a steep learning curve that kills you is to be avoided! For a short while I worked where electric cars (and IC cars) were being assembled and there were large GRP "shepherd's crooks" at regular points along the line for fishing out 'zapped' staff - scarey stuff.

IanA · #**284** 21st January 2021, 21:53

GRP shepherd's crooks!!! It's surprising just how low a current is required to kill if applied in the wrong place.

That's why I was so glad to see how heavily fused the Z3 is. It's a relatively large battery and even cheap ones can provide a cranking current >400A. That's probably why the later cars have the "explosive" cutout in the starter circuit.

Mitchelkitman · #**285** 21st January 2021, 22:33

Isn't it the Volts that kill? In the car being built ISTR it was 450V.
I wasn't involved with them (I'm pleased to say)

Mister Towed · #**286** 22nd January 2021, 08:46

I'm no electrician but I believe it's the current and length of time exposed that kill, the voltage is only relevant in terms of being able to 'push' enough current to do the job. Hence, police tasers run at around 50,000 volts and 18 amps, but it's delivered in bursts measured in microseconds, so is non-lethal (in most circumstances), while a domestic, 13amp, 240v socket is likely to kill you if you touch its insides without an RCD in the line.

As for electric cars, Trumpton are bloody terrified of them. We had a Nissan Leaf involved in a minor shunt (no pun intended) on my patch when I was a plod and the fire service treated it like an unexploded bomb, cordoning off the area, leaving it time to 'soak' and looking very anxious indeed when they started trying to disconnect things.

God help us all when everyone's driving electric...

IanA · #**287** 22nd January 2021, 10:59

On the electrical installations I've been involved with, we're talking 800kVA here, there's been an easily accessible breaker capable of handling that to shut it down. Usually some big red buttons, suitably relayed to do it as well.

My Fury has a battery isolator on the dash. I have a "magnetic ball" cut-out for my Jago.

WorldClassAccident · #**288** 22nd January 2021, 12:51

If you think of electric flow like a river

Volts = How fast the water is flowing
Amps = How much water is flowing past
Power = How hard it is to walk across

molleur · #**289** 22nd January 2021, 13:33

brilliant! Never heard that one before. Perfect!

Mitchelkitman · #**290** 22nd January 2021, 16:29

I'm very pleased my 12V 600 cca car battery won't kill me, even if I put my thumbs on both terminals at once (contrary to what the missus would expect), but I wonder what 'combination' is required? I'm not about to experiment (contrary to what the missus may hope

). In addition to my car battery I'm also aware I've had shocks involving probably several thousand Volts, but miniscule amps from static electricity. Somewhere in the mix is the lethal voltage/current mix - does anyone here know?

molleur · #**291** 22nd January 2021, 18:02

from 0.1 to 0.2 amps could be lethal.

Mitchelkitman · #**292** 22nd January 2021, 18:10

Quote:

Originally Posted by molleur

from 0.1 to 0.2 amps could be lethal.

At what voltage? I've been connected to 600 A at 12V with no known problem (apart from an inquisitive mind

)

Lucky@LeMans · #**293** 22nd January 2021, 18:30

I touched an electric fence as a kid just to see what it felt like ! Knocked me off my feet ! As an adult I've put my fingers in the wrong place on several occasions but I'm still here !

WorldClassAccident · #**294** 24th January 2021, 13:50

I got a kick from an electric fence when I tried to fry a grass hopper. I learned that the current went straight through the grass hooper AND me before earthing. It was a learning experience I still remember.

I have had a few kicks from 240V domestic such as the time I was working on the pump in the pond and the wife thought turning the power back on so the garden lights might help. Tingles a bit as long as it is only a quick connection but the 3 or 4 seconds before she realised did seem quite a long time.

Remember holding the square 9V batteries against my tongue as a bet when I was a kid which also was refreshing.

Mister Towed · #**295** 24th January 2021, 18:36

Quote:

Originally Posted by WorldClassAccident

I have had a few kicks from 240V domestic such as the time I was working on the pump in the pond and the wife thought turning the power back on so the garden lights might help.

"Oh, you're okay. I mean, thank goodness! I, er, thought the garden lights might help..."

IanA · #**296** 25th January 2021, 08:30

I did get an interesting belt once from a moped engine I was playing with. Kept me doubled up for a few seconds. It was a Powerpak 50cc bicycle add-on. Basic Wipac magneto ignition.