Hey gang, what's the typical output in KWh (or Amps) of 'destination' (non-Tesla) chargers out there? Just curious about that. Want to compare it to my home NEMA 14-50 outlet, which charges at 32A from the mobile cable, which is about 32 miles per hour (according to the screen's rate), so roughtly 1A per mile of range per hour. Need to translate amps to KWh, but I think the car says like 6, which would mean like 5A per KWh, therefore Tesla's superchargers should put out about 750 Amps (32/6=5 x 150 = 750). However, 750 miles per hour of charge doesn't sound right, so where is the error? Probably because superchargers are DC current (vs AC from my house), so how can we compare apples to apples, such as miles per KWh?
At any rate, let's see what the 'destination' chargers put out. By the way, I was going to take my mobile cable, but will probably leave it connected to the garage. There's a supercharger like 5 miles where I'll be staying. And I'll carry the 'destination' adapter, so don't think it's worth taking the 115V cable. I'll have to use (free) superchargers for about 1,300 miles. It shouldn't be detrimental to the battery pack, right? Thx.
The error is using only amps as both a power and energy measure.
- Energy (kWh) : A quantity, e.g. like gallons of gasoline.
- Power (kW): A rate of energy usage. Much like horsepower.
You get power by multiplying
voltage and amperage. With power, you multiply the average power by time to get energy (that's why the "h" is there).
A typical destination "non-Tesla" charger in North America (J1772 plug) is a 30A station, with the voltage being either 208V (commercial electricity) or 240V (residential). Even though both are 30A, you get more power out of a residential one (7200W or 7.2kW in theory) versus the common commercial setups (6240W or 6.24kW) simply because the voltage is different. This means if you go by the charging rate "miles per hour" on screen, they will actually vary between these two setups as well since their
power is different.
That is further why Superchargers need less amperage than you might expect. They're directly feeding in around 350-403V DC, thus need less amperage for equivalent powers.
No need. 50 kw chargers usually give 42kw (well... in Aus they often drop to 35) so as long as you charge faster than you consume thats ok.
Model 3 uses around 240wh/km at 150kmh. So thats 150 x 240 = 36kw/hr. So you still charge faster. At such high speeds the difference between charging and driving isnt really very pronaunced so whether you drive 160 or 150 or whatever doesnt make much difference. anything above is a treat on the autobahn nowadays anyway...
Again, life is a lot more complicated than that.
At 240Wh/km, I'm arriving at a much lower SoC (if I arrive at all due to the higher consumption?). At a Supercharger this would mean faster charging, but not at a 50kW CCS/CHAdeMO station since they'd be
current limited instead of
voltage limited. At low SoC I've seen something like 32kW net into the pack, but could still be lower. But notably, that's beyond your 36kW threshold.
Also, again, this relies on ludicrous amounts of planning, ideal charger placement, etc. That's not really how roads and population centers work, and is fair beyond a reasonable expectation of using a vehicle. Remember the context of this thread: frustration.
Getting optimal charging times is already a chore on trips, and travel at much greater than 120km/h is highly illegal and unsafe pretty much everywhere... especially in winter. Restating, high speed travel should not be treated as a general benefit for time-efficient road trips. There are many problems with that when applied to almost all real-world routes.
