Thread: EV general discussion

Originally Posted by Homestar

(I=1000xP/V) where I is the current and P is the power in KW and assuming no losses and flat batteries ready and able to take that current flow - you know what sized plug and cable that would need to be!

you dont need to be an Electrician. this is high school science.

Originally Posted by Homestar

As an Electrician, I find the KW output he chargers a little confusing to be honest - as per this article, it says up to 350KW for supported vehicles - let’s say we’re talking a Tesla here (we aren’t, but for the calculation) - they run at 375 volts DC. If this was the sort of vehicle they are talking about, that’s a current draw of over 900 amps (I=1000xP/V) where I is the current and P is the power in KW and assuming no losses and flat batteries ready and able to take that current flow - you know what sized plug and cable that would need to be!

I get this would be a peak current and that this drops as the charge comes up, but still, we’re talking about moving a massive amount of power in a short time over a consumer grade connection that has to be able to be used by anyone.

Don’t get me started on the fault currents either and how these are mitigated in the event of an issue - we’ve all seen the video of that Tesla exploding - a very real scenario if your charger’s capable of delivering nearly 1000 amps at over 350 volts - big badda boom as the Fifth Element would say.

So, what sort of current are the plugs and cables actually capable of supplying as I call BS on a hand held plug and cable delivering that sort of current or anywhere near that - anyone who’s tried to connect a 125 amp lead knows this is a struggle on you own - no way a little old lady doing her shopping could connect anything remotely capable of these sort of currents.

Assuming here that the chargers are delivering a DC current and not a 3 phase AC that is rectified on board the vehicle - happy to be corrected if that’s the case (but that’s still over 600 amps at 415 volts with a PF of 0.8...)

Nah,you got it all wrong,just plug it into the solar at home,easy as

On a serious note,I just imagine how much power you need for 50 plus chargers at a charging station,and the cost of the set up and the cost of the power......

Originally Posted by Eevo

you dont need to be an Electrician. this is high school science.

Correct but most people wouldn’t know what a KW or amp even is or what it takes to move large amounts of power - I know this because I talk to people every day about their power needs, and even Commercial and Industrial Electrical’s don’t understand a lot of this, so hows Joe Blogs supposed to? They just read this guff and thing ‘Wow, what an age we live in’ without any thought to the actual Science behind it.

Originally Posted by rick130

Auto correct with Swype keyboard on the phone.
It'll change words once a sentence has been completed trying to correct grammar and sentence structure.

You should see some of the doozies on the work tablet!

For a start I thought you may have already been at the Pub, but the post was at 9.34am so maybe a bit early - but if that’s your thing, I don’t judge you. 😆

Originally Posted by Homestar

Correct but most people wouldn’t know what a KW or amp even is or what it takes to move large amounts of power - I know this because I talk to people every day about their power needs, and even Commercial and Industrial Electrical’s don’t understand a lot of this, so hows Joe Blogs supposed to? They just read this guff and thing ‘Wow, what an age we live in’ without any thought to the actual Science behind it.

The average Fan Mechanic,i mean AC tech would have no friggin idea either.

But then again a good Fridgie would have it all sorted.....

Originally Posted by Homestar

For a start I thought you may have already been at the Pub, but the post was at 9.34am so maybe a bit early - but if that’s your thing, I don’t judge you. 😆

But it was 5 o'clock somewhere

Was trying to repair a 780kw chiller on top of a shopping mall.
The emphasis on trying...

BTW, reasonable size cables running into it, can't recall how many amps it pulls at 100% load but it's a few.

Originally Posted by Homestar

Correct but most people wouldn’t know what a KW or amp even is or what it takes to move large amounts of power - I know this because I talk to people every day about their power needs, and even Commercial and Industrial Electrical’s don’t understand a lot of this, so hows Joe Blogs supposed to? They just read this guff and thing ‘Wow, what an age we live in’ without any thought to the actual Science behind it.

I'm not an electrician, but I note Chargefox says it's 350kW chargers can deliver 400 Ks of charge in 15 minutes, which is impressive.

Australia's largest ultra-rapid EV charging network expands into New South Wales - Chargefox

A wide range of home chargers are available.

All - EVSE Australia

Originally Posted by DiscoMick

I'm not an electrician, but I note Chargefox says it's 350kW chargers can deliver 400 Ks of charge in 15 minutes, which is impressive.

Australia's largest ultra-rapid EV charging network expands into New South Wales - Chargefox

A wide range of home chargers are available.

All - EVSE Australia

You’ve just proved my point which I thank you for, not having a go at you here - you don’t understand what 350KW is so just think the number is impressive without knowing why - my question remains - HOW does it do this through what looks like a very small cable and plug? 900 amps would blow it to bits instantly. Some fudging of the figures me thinks...

FYI - this is the sort of size cable you’d need to handle 900 amps - and this is just one of them - 500mm sq. Brown/Brown 6381Y Cable Double Insulated Power Cable and you need 2. Note the cable thickness is around 38mm on its own and weighs around 5 Kg per meter, so a 3 meter lead made up of a pair of these would be 30kg - I’d like to see an elderly person plug that into their car...