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Mobile Connector Charge Time going up?

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Hi everyone!

Just joined the Tesla Family with a beautiful 2022 Model Y Performance. Just took delivery about 2 weeks ago and we absolutely love it.

Now on to my question, I purchased a mobile connector off Facebook marketplace prior to delivery of the MYP and for the first appx week and a half I used the standard mobile wall plug connector with no issues. We would drive it to about 57% and plug it in daily to make sure we would have the 80% charge daily limit. At first this was no issue as charge time was between 12-13 hrs using the standard plug in our garage.

The last 3 days I noticed that we have not been reaching our daily 80% limit… the first time it happened I noticed that when I plugged in the charger, and started the charge it stated 13 hrs to reach 80%. I started the charge at appx 6:30 pm meaning by 7:30 am the car would be at 80%. The next day I woke up at 7am and noticed that it said there was still 6 hrs left to reach the 80% charge limit…

At first I thought maybe I was going crazy, but then similar situation the following day. Just today I legit started the charge and looked at the charge time listing 13 hrs at 7:30 pm to reach 80% charge. I waited I wanted to say 10 mins and when I went into the app to check the charge time it showed 13 hrs and 10 mins. Charge time went up 10 mins?

Do I have a faulty mobile connector or do I have an issue with my outlet??
 
What does your app show for charge current and voltage? My wall connector on a 120v, 15 amp circuit shows 12 amp. If I charge at say 7pm it will show 119V and if offpeak like 1am it will show 121V so assume grid droops at high demand. If possible, you could try a different outlet to isolate problem.
 
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What does your app show for charge current and voltage? My wall connector on a 120v, 15 amp circuit shows 12 amp. If I charge at say 7pm it will show 119V and if offpeak like 1am it will show 121V so assume grid droops at high demand. If possible, you could try a different outlet to isolate problem.
Thanks for the reply. I was thinking about doing this as well. My app shows 12 Amps/114-115 Volts this very moment.
 
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If the weather has gotten colder, more energy from the wall is needed to keep the battery warm during charging so your charge times will increase as temperatures decrease overnight. Even though the draw is still 12A, much more of the energy is diverted to heating than when the area around the car is warmer.

This is why L2 (240V) is much more efficient, there is more energy to account for losses due to heat.
 
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I second @Mrbrock. One 5F day in January, the SO plugged our M3 into a heavy duty 120VAC extension at a friend’s house. Overnight, it added maybe 10 miles of charge, fruitlessly trying to get the battery warm enough to charge. On a 15 A circuit, running at 12A, you get 1.44 kW of power. Which is enough to toast a slice of bread, but warming up that huge battery down there, not so much.

The Mobile Connector can do 240VAC at 32A; that’s 7.68 kW, more than enough to get the battery warm, at which point you’re off to the races.
 
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Thanks for the reply. I was thinking about doing this as well. My app shows 12 Amps/114-115 Volts this very moment.
What is the voltage when no current is flowing? If you are dropping more than a couple of volts when current is flowing I would suspect your connector or circuit. Car will charge slower at low temperature but the voltage at the connector shouldn’t change be affected.
 
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The charging session could have been interrupted multiple times. The Mobile Connector would reduce the charging amperage before continuing to attempt to charge.

Common causes:

Old worn out power outlet (receptacle). Replace the old receptacle with a good quality commercial grade receptacle. Use the screw down terminals, never the push in terminals on the receptacle to connect the wiring.

Allowing the Tesla Mobile Connector to hang down supported by only the receptacle and the power plug adapter. Tesla sells a Cable Organizer that includes a mounting bracket for the Mobile Connector chassis. You can also find similar organizers on Amazon, eBay or Etsy. You can fashion your own means of supporting the Mobile Connector to relieve the strain from the power plug.
 
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As a few have said above there are energy losses. I'll try to go into more details. The charging session for 110/120V is only somewhere 60-80% efficient - meaning what percentage of energy goes into the battery pack. If your car says it'll take 1 hour to charge it'll actually be around to 1 hour 18 mins at 30% loss.

There are charging losses due to trying to heat up or cool down the battery. It takes energy to either of those things. At 12A @ 120V only ~1.4kW is flowing though the wires. I don't know the official number, but it takes some power to run the car. I've heard it's somewhere around 300W. So only 1.1kW is actually flowing into the battery. If the battery is warming or cooling, it needs energy so that will be even less actually flowing into the battery. It varies every night.

I was charging 120V when I first got my MYL. I observed that if I wanted my SOC to be at a certain level by the time I needed to leave, I had to factor in the inefficiencies of 120V of between 20-40% loss. If it needed about 10% charge overnight, I had to adjust the schedule leave time by 30 mins. If it needed 20% charge, it needed to be 1 hour. Your milage will vary since every outlet is different and the temperature conditions.
 
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If the weather has gotten colder, more energy from the wall is needed to keep the battery warm during charging so your charge times will increase as temperatures decrease overnight. Even though the draw is still 12A, much more of the energy is diverted to heating than when the area around the car is warmer.

This is why L2 (240V) is much more efficient, there is more energy to account for losses due to heat.
Yes, this actually might be it. Thankfully I’m waiting for electrician this moment to come out and install the Tesla wall charger. It warmed up these last two days in jersey and waddayaknow better charging time.
 
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