Omni Richmond Hotel ClipperCreek charger (need twin chargers to take full advantage)

[jthompson]

I have charged at the Richmond Omni Hotel on three different occasions. All three times I have received 70 amps (43 miles per hour of charge) all three times from that charger. (I do have the dual chargers, and I bumped the setting up to 70 amps [the Model s thinks this charger is a Tesla HPWC]). If you have a single charger, as noted earlier in this thread and on the Tesla website, you will only get 40 amps max.

 

[PaceyWhitter]

Forgive my ignorace (I am still trying to learn as much as possible) but why can't a single charger accept a more than 40A when the voltage is lower? I thought the single charger was rated for 10kW, which would equal about 240V and 40A. If the industrial voltage is lower, why can't the amperage be increased to compensate (when it is available as it seems to be in this case)

I'm sure there is a very good reason I just don't know it.

 

[islandbayy]

Forgive my ignorace (I am still trying to learn as much as possible) but why can't a single charger accept a more than 40A when the voltage is lower? I thought the single charger was rated for 10kW, which would equal about 240V and 40A. If the industrial voltage is lower, why can't the amperage be increased to compensate (when it is available as it seems to be in this case)

I'm sure there is a very good reason I just don't know it.

It is drawing 40 amp. 40 amps at 208v. 40 amp is 40 amp. It's maximum is 40 amps regardless. If it was on a 120v line, the maximum it can draw is still going to be 40 amps. 40 amp at 120v is only 5kw. The higher the voltage, the less resistance. So their is less resistance at 240v then their is at 208 or 120. Meaning at the higher voltage, more "watts" can be pushed through the "line" without increasing the amperage. Once you exceed somethings rated amperage, you get higher resistance. Higher resistance = more heat build up = wasted power as heat= less efficent.
That is why we also have circuit breakers. If you have something consuming more power (higher amperage) then what the wire size was designed for, the breaker trips. If it did not, the wire would quite literally turn into a toaster wire, and start a fire.

 

[FlasherZ]

Forgive my ignorace (I am still trying to learn as much as possible) but why can't a single charger accept a more than 40A when the voltage is lower? I thought the single charger was rated for 10kW, which would equal about 240V and 40A. If the industrial voltage is lower, why can't the amperage be increased to compensate (when it is available as it seems to be in this case)

I'm sure there is a very good reason I just don't know it.

Tesla does us a bit of a disservice with the way they advertise their chargers, by calling it a 10 kW charger instead of a 40A charger. But they're in a bit of a pickle no matter how they specify it, because kWh are what gets stored. Wire size, circuit board trace size, etc., is purely based on current, not power. The cabling and internal wiring of chargers in the US are sized for 40A continuous loads. The truth is that the US chargers in the Model S are capable of 11.08 kW, if you have access to a 277 VAC source (most people don't, and so 10 kW is a nice round number for Tesla to use).

Each of Tesla's chargers handles up to 40A, no matter the voltage (85-277V), so the max charger power is between 3.4 kW and 11.08 kW, depending upon the voltage you can offer it.

If you had 50 amp capability at 200V, it would be the equivalent power going into the car as 40A at 250V; the problem is that the cables to, and inside, the charger would need to be larger to accommodate the higher charging current (25% more).

 

[Cosmacelf]

The reason is wire size. More amperage (or current) requires thicker wires to stay at the same temperature. Even if you only had 12V, but tried to shove 100A through a 50A rated wire, it could melt the insulation.

 

[SFOTurtle]

I don't have dual chargers.

So how many amps and charge speed did you think you would be drawing at a non-SC charger without dual chargers? Was this the first time you've ever taken your car on a road trip?

If you had read the posts in the thread that you started a couple weeks ago, you would have seen the numerous posts discussing the need for dual/twin chargers to take advantage of 70A at this location. Charges in Richmond?

Why call out and criticize Tesla for this charging station and say it is a "disaster" when you were given plenty of notice about it and the need to have dual chargers to take advantage of the higher charging speed? Moderators: I might suggest revising the title of this thread because this charger is working within the range of normal and is not a "disaster" for anyone who has twin chargers.
Anyway, for those without twin chargers or a SC on your route, you need to plan for much longer stops or shorter trips. But with twin chargers and SCs, much more freedom.

I've used these Clipper Creek Roadster chargers a dozen or more times throughout California, and charge rates vary from low 40s to as much as 50 mi/hr depending on voltage, but my car has twin chargers.