EV Tales

Smoke on the way to the Funeral

The other day I was on the way to the funeral of my Uncle Hans. Uncle Hans was born in Germany, and like many people came to Australia after World War Two. He was rather unique in our family – at the end of WW2 he was plucked out of school as a teenager and served briefly on a u-boat. However fuel was short so he was send off to fight the Red Army, and ended up spending 12 months as a Russian POW. He also played the trumpet rather well, and spent much of his working life here in Australia helping his wife (my Aunty) run old folks homes here in Adelaide.

Anyway, here I was climbing a hill on the way to the funeral when suddenly the EV loses power and a puff of smoke appears at one side of the bonnet. Oh Dear.

I initially thought the worst – a popped Curtis Controller, worth AUD$2500. However on popping the bonnet I could see nothing wrong, and the controller was only just warm to touch. However I did notice a black sticky line where one of the instrumentation wires used to be.

Took me some figuring but eventually I worked out what had happened. I think I accidentally bumped the linkage inside the car for the emergency stop button. This button is required inside all EVs, and in my car manually trips the circuit breaker, cutting all power to the motor. On reflection, this linkage runs a little too close to the foot rest and I must have bumped it, shutting down the car.

Unfortunately at the time about 100A (12kW at 120V) was flowing through the traction wiring circuit. When the breaker opened, the parasitic inductance tried to keep that current flowing through any path possible. In my case the segment of poor instrumentation wiring that is connected between the two batteries either side of the breaker.

About 50cm of wire of 1mm wire and it’s insulation vaporised in an instant.

Every now and again you get a little reminder of the energies you are messing around with in EVs……

I flicked the breaker back and all was well. Driver error, plus a dumb wiring decision. Have now fused the instrumentation wire, like I should have in the first place! So I arrive at the funeral but unfortunately no sign of Uncle Hans or for that matter anyone else – the funeral date had been moved and no one had told me!

EV to the Rescue

Several days a week we electro-commute down to Day Care to drop off and pick up my 3 year old, Michael. Young Michael, like my wife, is quite convinced the EV is his: “Ikle-car Daddy-car” he calls it.

On this particular day one of the other Mums had her car stranded in front of Day Care and was asking people if they had jumper leads. This was a 35C summer day and she had a couple of little ones in the back. I didn’t have any leads but then it occurred to me that I had no less than 10 very high performance car batteries in my EV and 2 spares in the shed.

So I EV-ed Michael home and dashed back with a pair of jumper leads and one of my spare Yellow Top EV batteries. I chose the spare battery as I was nervous about tapping one battery out of my 120V series pack – a wrong connection would start her car just a little too vigorously!

Anyway my spare EV battery started her car in about 1 second and off she went. I thought it was pretty cool that an EV had rescued an ICE :-)

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