cwerdna
Well-known member
Miles per hour is only accurate for a given vehicle assuming a certain efficiency (e.g. miles per kWh or watt-hours per mile), which may or may not have a published constant. And, if you achieve less than that constant, each "mile" isn't worth a mile and vice versa.coleafrado2 said:Forget kilowatt-hours and kilowatts. Let's just talk in terms of horsepower and miles per hour.
How do you like tables like these?
https://www.tesla.com/support/home-charging-installation/wall-connector
https://web.archive.org/web/20180922075332/https://www.tesla.com/support/home-charging-installation/wall-connector <-- this isn't even accurate for many cases like the Model S that were sold with twin (almost) 10 kW (40 amps each) OBCs. It's not accurate for later Model 3's as they later could be had w/48 vs. 32 amp OBCs. There are older tables which I'd have to dig up that accurately reflect the Model S w/80 amps of OBC.
Also, eventually, Tesla stopped equipping vehicles in the US w/40, 72 and 80 amps of OBC. They max out at 48 now. Seems like they only are 48 and 32 amps now per https://www.tesla.com/support/home-charging-installation/onboard-charger. (https://web.archive.org/web/20180915023127/https://www.tesla.com/support/home-charging-installation/onboard-charger shows 72 being a choice before.)
The above tables aren't accurate for 208 volts either (common for commercial power and the voltage at my work). You need to multiply all of those by 0.866.
At work, before COVID, a Tesla driver in Slack might say, I'm getting nn mph. Is that right? How the heck should I know? I need to know which vehicle and OBC they have, at a minimum. They should tell me what voltage they're seeing and amps (visible in their car and in their Tesla app). Voltage might be a little low at that spot or that day.
Besides the 30 amp max output ChargePoint CT4000 stations, we have a bunch of gen 2 Wall Connectors (https://www.tesla.com/support/home-charging-installation/wall-connector-second-generation) in a power sharing arrangement. Each pair was on a 100 amp circuit for 80 amp max draw. If two vehicles were connected drawing full power w/40+ amp OBC, each side would only get 40 amps, until one ramped down, finished or was unplugged.
Let's go by values that aren't dependent on crazy, almost always inaccurate, often unpublished and varying constants.
I have never used an L2 EVSE or DC FC that has a display that tells me how many ""miles" per hour" I'm getting. Even if it did, it's of no value to me due to needing know the constant they chose vs. how many mies/kWh I expect to get.
1 hp = ~746 watts