Anyway want to get ahead making a 1/2 Megawatt charger? - Page 1
Forum section: electronics / general

author: paulca
author_rank: Super Contributor
timestamp: October 30, 2019, 06:17:31 pm
content: https://www.independent.co.uk/life-style/gadgets-and-tech/news/electric-cars-battery-recharge-time-a9177781.html?utm_term=Autofeed&utm_medium=Social&utm_source=Facebook&fbclid=IwAR3QwmJmtd4B_bfH05i6Z87T8wysjdKkSW53mCRFvReSbjfDFT0yzrv8h3A#Echobox=1572448893They basically claim they have a breakthrough that will mean Tesla S sized car batteries can be charged in 10 minutes.Tesla S battery = 85kWh.1 hour charge = 85kW.10 minutes charge = 510kW.At 240V that's at least 2100Amps.At 11,000V that's around managable at close to 50 amps.Of course the press are all over it without thinking it through even slightly.

author: MagicSmoker
author_rank: Super Contributor
timestamp: October 30, 2019, 06:27:54 pm
content: The general way to make this kind of fast charger practical is to have a local "buffer" battery that is continuously recharged by the grid at a reasonable rate and then have the fast charger draw the high peak power from it rather than directly from the grid.

author: paulca
author_rank: Super Contributor
timestamp: October 30, 2019, 06:29:36 pm
content: Quote from: MagicSmoker on October 30, 2019, 06:27:54 pmHow do you get it from that buffer battery to the car? Cable to carry 2100 amps is not going to be movable by your average punter and cable that can will need to run at many kilovolts which has many other issues.

author: MagicSmoker
author_rank: Super Contributor
timestamp: October 30, 2019, 06:40:17 pm
content: Quote from: paulca on October 30, 2019, 06:29:36 pmCarrying that current for 10 minutes with an acceptable temperature rise isn't that difficult; 25mm diameter cable will do. The buffer battery voltage should be much higher than the EV battery voltage and the isolation from the mains should be provided by the (relatively) lower power buffer battery charger so that a simple buck converter can be used as the high rate EV charger. It's cumbersome and a costly setup to be sure, but so is running MCM750 a few thousand feet to a massive pad-mount distribution transformer.

author: Nauris
author_rank: Regular Contributor
timestamp: October 30, 2019, 06:45:39 pm
content: Quote from: paulca on October 30, 2019, 06:29:36 pmSome performance cars have a 800 volt battery then it is only 600 amps that should be no problem. Think for example 400 amp MIG welder handle, it is quite light and flexible actually. It just needs water (or oil) cooling.

author: paulca
author_rank: Super Contributor
timestamp: October 30, 2019, 07:19:03 pm
content: If it was to be implemented, and lets say they address how they enable users to connect that amount of power to a domestic car safely, the infrastructural and engineering required would be huge. In it's early development it would be limited to fewer "super charge stations", so rather than waiting on your car charging you'll spend it waiting in the queue to use the charger.Made me laugh but I just envisioned a BP tanker truck driving down the road with two leads sticking out the back, a stripe down one side and a + on the other. How many Farrads would that store.

author: max_torque
author_rank: Super Contributor
timestamp: October 30, 2019, 09:48:50 pm
content: Phoenix contact already do an internally water cooled CCS charging handle, rated for 500amps, which is of course, 0.5 MW at 1kV...https://www.phoenixcontact.com/online/portal/pi?1dmy&urile=wcm:path:/pien/web/main/products/technology_pages/subcategory_pages/High_power_charging/b1c8a245-f088-4fad-b144-cea31e7f9a82Used for the high performance Taycan CCS chargers by Porsche

author: ejeffrey
author_rank: Super Contributor
timestamp: October 30, 2019, 10:26:45 pm
content: Quote from: paulca on October 30, 2019, 06:29:36 pmTeslas do supercharging at >400 volts, the Porsche Taycan charges at >800 V. So that is "only" around 625 amps. Perfectly manageable with the right cable and cooling.QuoteOf course this is for supercharger stations not home use. There is almost no point in charging faster than a standard 9 kW (powered by a regular dryer or oven outlet) for home use. The point is to get as close to parity with gas station refueling while still allowing the advantage of charging at home or work where your car typically spends hours parked anyway.

author: Circlotron
author_rank: Super Contributor
timestamp: October 30, 2019, 10:47:15 pm
content: The magnetic forces around the cables might have some unforeseen effects on watches, smart phones, medical implants etc.

author: ejeffrey
author_rank: Super Contributor
timestamp: October 31, 2019, 03:53:06 am
content: 600 amps creates a 20 gauss field at a distance of 5 cm. That is ~10 times less than a refrigerator magnet and most of it will be cancelled by the return current flowing through the same cable. Once you account for cancellation from the return path it is likely to fall off to less than the earth's magnetic field (0.5 gauss) within a foot, or could be cancelled almost completely if desired by adopting a coaxial geometry.So it might be enough to mess with a compass at short range. According to a quick internet search, pacemakers should not be subject to fields over 10 gauss, which seems easy to avoid. Nothing else is particularly sensitive to weak DC magnetic fields.

author: EEEnthusiast
author_rank: Frequent Contributor
timestamp: October 31, 2019, 04:10:29 am
content: May be one day the electric car charging would be using lightning strikes at very high voltage . You park under a giant capacitor which is charged to few million volts, which would provide the car with multiple lightning shots in a couple of minutes. The car batteries would get charged from those strikes. Each strike would transfer a few million Joules of energy. And each car would have a lightning arrestor antenna sticking from the top, to receive those jolts.Does this sound like science fiction?

author: ogden
author_rank: Super Contributor
timestamp: October 31, 2019, 05:55:33 am
content: Quote from: EEEnthusiast on October 31, 2019, 04:10:29 amLOL, yes indeed. There's pre-existing design for moving cars BTW:

author: EEEnthusiast
author_rank: Frequent Contributor
timestamp: October 31, 2019, 06:17:33 am
content: LOL, yes indeed. There's pre-existing design for moving cars BTW:That looks really dope..

author: ConKbot
author_rank: Super Contributor
timestamp: October 31, 2019, 08:46:31 pm
content: "New battery in startup/university lab charges in X seconds, EVs that charge in minutes coming! "Oh look, this thread again. Same shit different month.

author: ogden
author_rank: Super Contributor
timestamp: October 31, 2019, 09:01:42 pm
content: Quote from: ConKbot on October 31, 2019, 08:46:31 pmBefore posting BS like this why don't youactuallyread article? Quote:Quote

author: ConKbot
author_rank: Super Contributor
timestamp: October 31, 2019, 09:53:13 pm
content: Quote from: ogden on October 31, 2019, 09:01:42 pmBecause when every post about X minute charge time EVs for the past 10 years has been the same stuff presented in slightly different manners, I can be bothered to read the original post, but not muster up enough care to click a link if nothing new looks to be presented. I can always rely on Cunningham's law and someone will post the details if they are actually interesting if I'm incorrect.

author: DenzilPenberthy
author_rank: Frequent Contributor
timestamp: November 01, 2019, 05:09:24 pm
content: Quote from: paulca on October 30, 2019, 06:17:31 pmThis is why three-phase is used for high power loads. Plus there is no requirement to use 240v.

author: paulca
author_rank: Super Contributor
timestamp: November 01, 2019, 06:19:32 pm
content: Quote from: DenzilPenberthy on November 01, 2019, 05:09:24 pmReally? Who knew. Maybe I should have picked a random voltage with no bearing on reality as a comparison point. like 156.7356V cause that would have helped put the point across.(sorry bad day at work)

author: ahbushnell
author_rank: Frequent Contributor
timestamp: November 03, 2019, 04:08:55 am
content: Quote from: paulca on November 01, 2019, 06:19:32 pm600A with three phase 480.