I thought we get 31 miles per hour with NEMA14-50

Yeah, you should get more than that. The display says you are at 236V and 40A, so it's not like you have greatly sagging voltage, or lowered current because your connector is not fully inserted.

My best guess (?) would be that you recently plugged in, and it diverted power to cooling the battery or something like that first. The number should rise after a while.

Do you have pre-4.0 software and your speedometer range set to Projected?

The +0 miles charged indicates this is right after you plugged it in. Give it a few miles of charge (5m or so) and the rate becomes pretty accurate and consistent.

Francis Lau said:

I have version 4.0 and I believe that with this version, I cannot set the speedometer range to projected. It is always rated, I think.

Does this affect charge rates?

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In pre-4.0, the Projected vs. Rated display setting impacted the reported charging rate (in miles) in the UI. AFAIK, it didn't affect the actual rate of charging.

In 4.0, I presume(d) that the Rated vs. Ideal has a similar impact but given that both Rated and Ideal are fixed numbers there isn't the same sensitivity to driver history that Projected had.

Francis, I was wondering the same thing - I usually only see about 20-21 mi/hr when I charge at home with my 14-50 outlet. I also see about 39-40 amps on the right side of the display - pretty much exactly what your picture shows above. I have never see anything above 21, not even close to the 31 defined by Tesla. I was wondering if the HPWC will make a difference when it arrives?

Francis -

First of all, congrats on software V 4.0. I'm still waiting for mine. I can tell you have yours since the picture you posted is not a red Signature Model S.

Secondly, the last picture that you posted shows the car at 238 miles. In my Standard charging mode (and I haven't made any adjustments to this - not sure if you are able to do so), that's about the limit that I charge to. Therefore, the car is getting close to it's max range in Standard mode and will automatically back down the charge rate (but that isn't indicated on the current draw).

You may want to take a picture and post it after about 20 mins. of charging but way before you hit 238 miles on the charge meter. If it is still only showing 20mph, then perhaps a screen reset will solve this (not sure, but just reaching for a possible solution).

Is it correct that you are at 90% SOC?

The charging slows down as you approach a full charge. It doesn't matter if you are plugged into a NEMA 14-50 or a supercharger, the battery will limit the charging.

Do you have a single or dual chargers in your car? I was told by a Tesla engineer that the cars with only one charger charge a lot slower than those with dual chargers. I got up to 29/miles with 40A at 203V on a NEMA 14-50 (but only after a while of charging). Have dual chargers.

I believe 4.0 has a bug where it's showing projected MPH for charge (even though you can't select project as an option anymore). I'm observing the same inaccurate number -- but it will vary quite a bit between sessions even with the same voltage and amperage -- and I believe that's because it's using projected range. I also did some math and it seems to line up wth that theory. I already let ownership know. I'm not sure if it's fixed in 4.1 (I haven't tested yet).

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Yggdrasill said:

Is it correct that you are at 90% SOC?

The charging slows down as you approach a full charge. It doesn't matter if you are plugged into a NEMA 14-50 or a supercharger, the battery will limit the charging.

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Not true for a standard mode charge at 240/40 in the Model S.

Futurist said:

Do you have a single or dual chargers in your car? I was told by a Tesla engineer that the cars with only one charger charge a lot slower than those with dual chargers. I got up to 29/miles with 40A at 203V on a NEMA 14-50 (but only after a while of charging). Have dual chargers.

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Single charger is 31mi/hr on 240volt. Dual charger is 62mi/hr but requires HPWC. Says so right on their page. http://www.teslamotors.com/charging#/highpower

I get 32 mi/hr at 40 A 243 volt
less if voltage is only 220 or so (Hopland)

edit: this was v .39 in rated

Zextraterrestrial said:

I get 32 mi/hr at 40 A 243 volt
less if voltage is only 220 or so (Hopland)

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Software version and range setting (projected/rated/ideal)?

I've found the display of miles per hour of charging is averaged over a long, long period of time. Right now my car shows 183 miles rated range, 1 hr 56 minutes remaining to charge, 245V @ 40A, although it shows 21 mi/hr charge rate. I've found the "remaining to charge" to be calculated correctly.

Your voltage is slightly lower, so your miles per hour will be lower, but only by 1 mph or so.

FlasherZ sounds right to me. In the first example there's about 125 miles of charge to go with a 3.75 hour estimated time remaining. That's about 33 mph.

yobigd20 said:

Single charger is 31mi/hr on 240volt. Dual charger is 62mi/hr but requires HPWC. Says so right on their page. http://www.teslamotors.com/charging#/highpower

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I was told that cars with only one charger take quite longer for all charges compared to those with dual chargers. The mechanics in the Tesla Center in Queens told me, that at their NEMA 14-50 outlets, the singe charger cars take almost 40% longer to charge than those with dual chargers (at the same outlet). It has to do with the fact that in the master-slave-configuration of the dual chargers, they even charge quicker if only 5 or 8 KW are provided.

Zextraterrestrial said:

I get 32 mi/hr at 40 A 243 volt
less if voltage is only 220 or so (Hopland)

Click to expand...

Do you have the time to post a picture of the screen when you are charging at that rate?? Thanks!

Try depleting your battery to low, plug in the car, wait 20 minutes and then check.