I think just a coincidence for you there was similar voltage drops at those places. When I’ve plugged into 120V I’ve commonly seen 116 or 117V at 12A.
-
Want to remove ads? Register an account and login to see fewer ads, and become a Supporting Member to remove almost all ads.
Charge percentage not increasing despite charging
- Thread starter Joelgjr
- Start date
murphyS90D
Member
I just did an experiment to show what is possible.
I have a 120 volt 20 amp outlet in my garage. It is fed by 75 feet of 10 gauge wire. I know that 12 gauge is standard for a 20 amp circuit but at that distance 10 gauge makes more sense. I have the 20 amp adapter for my UMC so that is what I used. Before starting charging the voltage at the outlet was 122.7 volts. It's above 120 because the sun is out and my PV solar panels are producing power. When the car started charging at 16 amps the voltage dropped to 119.0 volts for a feed cable loss of 3.7 volts. The loss in the cable is 3.7 * 16 = 59.2 watts (ignoring power factor). 59 watts distributed over 75 feet of cable means very little temperature increase in the cable. The temperature in the garage was 72° F.
I have a 120 volt 20 amp outlet in my garage. It is fed by 75 feet of 10 gauge wire. I know that 12 gauge is standard for a 20 amp circuit but at that distance 10 gauge makes more sense. I have the 20 amp adapter for my UMC so that is what I used. Before starting charging the voltage at the outlet was 122.7 volts. It's above 120 because the sun is out and my PV solar panels are producing power. When the car started charging at 16 amps the voltage dropped to 119.0 volts for a feed cable loss of 3.7 volts. The loss in the cable is 3.7 * 16 = 59.2 watts (ignoring power factor). 59 watts distributed over 75 feet of cable means very little temperature increase in the cable. The temperature in the garage was 72° F.
yes, I am also in Boston, but I have a garage - it was in the high 60s all night inside the garage
I charge at work to 80%. I normally don't charge at home but since I had just returned from a trip I wanted to get the car up to a reasonable SOC.
Per later posts I created, I upped the charge to 80% and allowed an additional 24 hours to elapse. I had "Always Connected" turned off and "Power Saving" turned on. I did not use the app during the 24 hours, nor did I sit in the car. The only way that I knew anything about the state of charge during the second 24-hours was by looking through the driver's window at the screen. The reason the screen stayed on was because I do not lock my car in my garage. During the second 24-hours, the SOC did not increase from 57% despite continuing to draw 12amps and being set to 80%. Conditions of the garage were around 67F. Car was definitely "off". Through the drivers window I could see the estimated time of charge rapidly cycling between "3 hours 30 minutes" and ramping up to "24-hours+" and then back down again.
I unplugged, and replugged, the mobile charger, and the vehicle immediately began charging at 3mph. Within 3 hours it hit 60%, something it couldn't do in the previous 24 hours. All other conditions were the same. The screen was no longer cycling between "3hours 30 minutes" and "24-hours +". It stayed on "3 hours 30 minutes" and counted down.
What I'm most concerned about, considering this car is under warranty so anything broken will be replaced, is where the hell did the 64kWh (12amps*112volts for 48hours with 0% in SOC) go - that's a ton of energy wasted! I'm trying to go green here - we have NG burning power plants in the Northeast.
Last edited:
Maybe it wasn't charging, did you see it say it on the IC after you plugged it in?
I considered that, but can confirm the following, which should prove it was charging:
- Screen said it was charging
- Screen showed estimated time remaining charging
- fan clicked on in front part of vehicle with vehicle off
- Screen showed ramp up from 0/12 amps to 12/12 amps
- Volts dropped from 119 volts to 111 volts as amps went up from 0/12 to 12/12
- My amp meter indicated 12.5 amps were being drawn off my garage circuit (I monitor total amps on my garage as I use power tools and compressors on only 20 amps).
- ring went from blue to blinking green
Brass Guy
Active Member
I have noticed on occasion a fan starting up after exiting and closing the car door. Climate control was off when I exited the car.
Once it did it in my garage, and I was curious if it was a cooling fan or the cabin fan. I knew from experience if I opened the driver door the fan would shut off. So I climbed in through the hatch, and it was definitely the cabin fan blowing. I'd guess as loud as it was it'd have to have been blowing at least at level 6, but with the screens off I couldn't tell for sure. I found it extremely annoying and wasteful.
If it does it while you're trying to charge on 120V, you won't get far.
Have you rebooted the screen? (Press both scroll wheels for about 5 seconds.) That fixes a lot of odd problems.
If it is the cabin fan, and you cannot get it to stop, try setting the climate manually to Temp:LO, AC: Off, Fan:1. If the setting sticks with the car off, that'd be the least energy draw you could force on it.
Once it did it in my garage, and I was curious if it was a cooling fan or the cabin fan. I knew from experience if I opened the driver door the fan would shut off. So I climbed in through the hatch, and it was definitely the cabin fan blowing. I'd guess as loud as it was it'd have to have been blowing at least at level 6, but with the screens off I couldn't tell for sure. I found it extremely annoying and wasteful.
If it does it while you're trying to charge on 120V, you won't get far.
Have you rebooted the screen? (Press both scroll wheels for about 5 seconds.) That fixes a lot of odd problems.
If it is the cabin fan, and you cannot get it to stop, try setting the climate manually to Temp:LO, AC: Off, Fan:1. If the setting sticks with the car off, that'd be the least energy draw you could force on it.
I think leaving the car unlocked is the problem. Your car is using wall power to run the displays and maintain cabin temperature.
Try locking the car overnight. I used the 6-15 adapter to charge my wife’s S100D to 100% in an unheated condo garage in Chicago in November. Car was locked, I monitored via iPhone App. Reached full range about 45 minutes before my friend and I started for Philadelpia.
Try locking the car overnight. I used the 6-15 adapter to charge my wife’s S100D to 100% in an unheated condo garage in Chicago in November. Car was locked, I monitored via iPhone App. Reached full range about 45 minutes before my friend and I started for Philadelpia.
My screen shows me what is going when I look in the window because it’s unlocked because I walked up to the car with the fob. 
. I’d turn on auto-lock, walk away, be sure the fob is far enough away from the car to keep the car locked (check with the app to be sure the car is locked) and I bet that is the problem, the car is awake all the time. Good suggestion on that one.
But 120V charging is really barely barely adequate, and isn’t good for home use. Perhaps for vacation use when that’s all you have.
. I’d turn on auto-lock, walk away, be sure the fob is far enough away from the car to keep the car locked (check with the app to be sure the car is locked) and I bet that is the problem, the car is awake all the time. Good suggestion on that one.But 120V charging is really barely barely adequate, and isn’t good for home use. Perhaps for vacation use when that’s all you have.
1) I keep climate off even when I’m driving the car
2) Yes I’ve restarted numerous times
My screen shows me what is going when I look in the window because it’s unlocked because I walked up to the car with the fob.
But 120V charging is really barely barely adequate, and isn’t good for home use. Perhaps for vacation use when that’s all you have.
I keep the fob inside the car, inside the unlocked car within the locked heated garage. When I get out the center screen goes dark, the music turns off, and the drivers screen displays the charge info. It’s not sensing me approach and retreat because the fob stays inside the car
There are two reasons why I’m not installing a dedicated 240v line to my Tesla:
1) parking at work includes charging, and there are always at least a couple open stalls
2) I’m moving out of my house in the fall so any investment in running the new outlet would be lost, which is compounded by the fact that my garage is a free standing structure, which necessitates burying cable to install the outlet, as well as the installation of a sub-panel due to local code. I got three estimates and the best was $2200. I’m having a hard time justifying that expense if I’m leaving in October.
3) bonus! At the top of my street is a free level 2 charger. Although based on things I’m seeing here, non Teslas have the right to unplug Teslas if they don’t like the way we looked at them
It hasn’t happened again since that one 48 hour period, despite all other variables being the same. Despite everyone saying that the mere act of using the app to check charge level would negate any charging that I might get from 120v, the reality is I am charging between 3 and 4 mph, with cooling fan clicking on and off, and I can check the app until the cows come home.
If you have other better charging, all bets are off.
And if the car is actually not awake all the time then that’s working, of course. Yeah, definitely sounds like that physical location is not worth installing more power at!Why would you do that? Wouldn’t this prevent the car from going to sleep?
hacer
Active Member
Sounds like you maybe have a door not fully latched, that would cause the screen to not time out for a long time. Also try explicitly turning off the A/C before plugging in the car.
hacer
Active Member
I'm pretty confident that power went into the climate control system even though you think it was off. It is consistent with the amount of energy wasted and the fact that you heard fans running. It could have been caused by an MCU glitch, exacerbated by leaving the keys in the car, which I think prevents the car from sleep mode which is the usual thing during charging.
I’ve been leaving keys in my cars inside the garage for decades. Just habit for convenience
I think you’re right - it’s the only thing that makes sense considering all the evidence
When driving a high tech, electric car we have to change our habits. I know I did, but that can also be the fun part.
The problem is that you are operating out of the norm. If a screen is on then it is using power. Plug it in, make sure the ring shows charging, take the keys and walk away.
If you really want to test to see if your car is broken, try it at another known good location with a 120v plug overnight and note any changing variable like taking the key and the car locking, or screens staying on. 120v charging works and can be viable. I used it on vacation just fine. You mentioned you were trying to “go green”. 120v charging is the least efficient way to charge, and wastes the most electricity. I suspect you want to charge places other than home to save money, which is why you are charging to only 60% and home and 80% other places.
Why not. I hope these ideas help you get to understand how your new car works.
Similar threads
