HPWC Charge rate issue

[Jonathan Scott]

hey everyone, tried searching but couldn't find what I needed..

So I bought and installed a HPWC (GEN2) the other day to charge my 2016 X 90D. all is well, it works just fine, the car shows 72amp available and 72amps selected but I am only getting about 36-38miles per hour. at first I thought this was just due to the car being cold but today we got home from a 200 mile road trip with less than 10% left on the battery and I am still only getting 36mph... any ideas?

as far as the installation goes, I ran #2 AWG Copper wire, 100amp breaker on my panel, and everything checks out electrically from what I can see, I heard of people having issues when they use the wrong gauge wire but doesn't that usually get reflected on the screen with the available amps?

Thanks again in advance!

 

[Lloyd]

What is your voltage available? If you are 208, then that would be about right with some drop on load.

 

[Jonathan Scott]

voltage is steady between 238-241.

Another experiment I just tried was I lowered the rotary switch setting to C which should be for a 90Amp breaker and now the charge speed went up to 45mph... weird

 

[qadaemon]

Every once in a while mine does this. If I hold the reset button on the HPWC for a few seconds and re-plug it, it goes back to normal. It's on a 100A breaker and set appropriately FWIW.

 

[Jonathan Scott]

Thanks, I tried that, also ironically, i'm away for work this week and I plugged into a destination charger at my hotel, same issue, car shows 72amp but only 42mph...

 

[ccdisce]

Three wks ago I Range Charged my 2017 S100D at a 'public' HPWC in Seaside FL ( thanks Dave) and it worked great , pic posted.

If you have the time and inclination you may want to check with your nearest SC to see if they have HPWCs that you could use to rerun your charging test.

If the fault is duplicated help is nearby as the 'fault' could be in the on-board charger... oh horrors.

 

[Rocky_H]

Thanks, I tried that, also ironically, i'm away for work this week and I plugged into a destination charger at my hotel, same issue, car shows 72amp but only 42mph...

I don't see that anyone has explained this part yet, which may relate to your question. The miles per hour number is not an instantaneous reading, so you may not be getting good information about the actual charging speed you have going on. The miles per hour is an average over the whole charging session. So if it is slowly ramping up for a couple of minutes, you are going to see a low-looking number as that average for a while as the low numbers are merged into the higher numbers later. Check on it after 20 or 30 minutes or so, and it should be a better estimate because the slow first couple of minutes won't be weighing into the number as much.

If you want to see an accurate reading (not an average) of your charging speed, go into the Controls--> Settings --> Units and find the one that selects whether to display as "Energy" or "Distance". If you switch it to "Energy", the battery meter will switch to reading % instead of rated miles, and the charging screen will show the rate in kiloWatts, rather than miles per hour. I don't really know why Tesla made this a different type of measurement, but the kiloWatt number is always an instantaneous reading, rather than an average like miles per hour is. So any time anyone has a question about whether the charging speed they are seeing makes sense or not, don't bother trying to go by the miles per hour reading. Switch it to Energy and see how many kW it says to see if the power level is right.