Model 3

Standard Plug Charging problem

I’ve been charging my M3LR at home off standard 120 volt. Problem now is I’m only showing a 5 amp draw where it used to be 12. I tried an alternate outlet, same issue. One time the car’s display screen was showing 5min remaining to charge with a 60% battery state set for 90%. Does anyone have experience with this problem? Is it more likely a problem with the car’s internal charger adapting logic or the wall charger unit that came with the car? I don’t see how to adjust the amps on the car’s screen or via the phone app. if that’s even an option. BTW internal charger logic recently adapted fine to an 8KW destination charger and a 150KW Super Charger.

Comments

  • Are you using scheduled departure? The car when plugged in may not yet be charging the battery. It will show on the screen amp usage, appearing at a glance that charging is occurring, when in fact it is showing current being used to maintain the systems like warm or cool the battery etc. I use a 14-50 240v outlet and see a small amount of current used routinely.
  • @Yormax let's take a step back here for a sec as there are a few things to verify first...

    First, on your charging screen when charging there is Amp + and - buttons on the lower left. Tap the + button a few time and see if you can get it back up to 12A.

    Second, again verify that your requested charge state is set for 90%. This setting gets geo-locked when you set it and it may have gotten messed up. So AFTER you start charging check to make sure it is set correctly, same with my first idea of the Amps + and - buttons.

    Third, and this is more just to mention because of it being winter time. If the weather is cold and your car is cold when you go to charge it, it may go and put some of the power toward heating the battery and NOT charging the car. I believe but could be wrong, that the Amp draw shown is strictly for charging the battery. So possibly, the other 7A is going toward heating the battery.
  • > @JVINFL said:
    > Are you using scheduled departure? The car when plugged in may not yet be charging the battery. It will show on the screen amp usage, appearing at a glance that charging is occurring, when in fact it is showing current being used to maintain the systems like warm or cool the battery etc. I use a 14-50 240v outlet and see a small amount of current used routinely.
    Thank you for your tip @JVINFL. I had disabled Scheduled Departure but your point is well taken as I try to get through this winter parked outside in the VA winter. Temperature has been getting down to 28F at night, so that no doubt challenges my relatively meager current.
  • > @derotam said:
    > @Yormax let's take a step back here for a sec as there are a few things to verify first...
    >
    > First, on your charging screen when charging there is Amp + and - buttons on the lower left. Tap the + button a few time and see if you can get it back up to 12A.
    >
    > Second, again verify that your requested charge state is set for 90%. This setting gets geo-locked when you set it and it may have gotten messed up. So AFTER you start charging check to make sure it is set correctly, same with my first idea of the Amps + and - buttons.
    >
    > Third, and this is more just to mention because of it being winter time. If the weather is cold and your car is cold when you go to charge it, it may go and put some of the power toward heating the battery and NOT charging the car. I believe but could be wrong, that the Amp draw shown is strictly for charging the battery. So possibly, the other 7A is going toward heating the battery.
    >
  • @derotam thank you for your helpful advice. I know the amp + and - you are referring to. I had tried it previously but the system symbols were grayed out and wouldn’t let me adjust. That said, your tip prompted me to try again and it was successful. The outside air temperature at the time was 52F. I don’t recall but perhaps my previous attempt was when the temperature was much colder and the system wouldn’t allow the option as per @JVINFL’s comments above. Thank you both! Problem solved for now.
  • > @Yormax said:
    > @derotam thank you for your helpful advice. I know the amp + and - you are referring to. I had tried it previously but the system symbols were grayed out and wouldn’t let me adjust. That said, your tip prompted me to try again and it was successful. The outside air temperature at the time was 52F. I don’t recall but perhaps my previous attempt was when the temperature was much colder and the system wouldn’t allow the option as per @JVINFL’s comments above. Thank you both! Problem solved for now.

    So I don't know at what temperature(battery) would trigger battery warming but it isn't as cold as you might think probably. You know those dots on your power bar on the right? Those limit your regen. At 52F for battery temperature you are going to see about 13 dots there.

    Also, the car will try to warm the battery even when I don't believe it really needs it, for example in your situation. You are only putting in 1.4kW and I don't think warming is as necessary as the car thinks. It acts a little brute force but it is better for the battery for it to act overall.
  • OK. First things first. I have actually tried charging a M3 in 20F weather using the 120 VAC approach to life. It doesn't work well.
    Main point: The batteries have to be warmed up enough to _accept_ the charge. In the 20F's, that tends to result in charge rates that, instead of being 4-5 MoCpH (Miles of Charge per Hour), it drops down to 1, maybe 2, and, if it's cold enough out there, 0.
    Now, in my case, it was the SO at a friend's house a hundred-fifty miles away, and they were trying to use an extension cord. And that, right there, is another demerit. Seems that if you really want effective charging, you want to use an extension cord that is _really_ _designed_ to handle 15A at 120 VAC. Most of the Home Depot/Grocery Store specials say things like, "Extra Rugged". "Extra Rugged" means, "Lots of Orange Insulation!" which is cool - but it's the expensive copper they all these types cheap out upon. And if there's too little copper, there's an extensive voltage drop; and the Tesla will detect that voltage drop and, in the interests of Safety, will reduce the charging current. So, instead of getting 12A, we were getting 8A.
    A trip to Harbor Freight will reveal a rack of extension cords that really _are_ rated for 15A; the longer the cord, the bigger the copper gauge, and they get more expensive in a hurry. On the other hand, they actually work, which is more than one can say for the Home Depot specials.
  • Tronguy-
    I think that’s the first time I’ve ever seen anyone recommend buying from Harbor Freight over Home Depot to get better quality. I thought I was the only one who thought HDs quality had slipped drastically.

    That said, HD does have Good quality extension cords, it’s just that they also have an awful lot of not so good ones.
  • See if you can use your house's dryer electric outlet instead. If you need an extension cord to make that reach, call the sales guy at EVSEadapters.com during regular business hours.
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