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Tesla Model 3 charging really slow at home?

RJUK

Member
May 31, 2019
58
8
United Kingdom
Hi folks, I've not long moved from a Jaguar I-Pace to a Model 3 Performance, and I have a 7kw home charger. The I-Pace had a 90kWh battery and the Tesla a 75kWh battery, so I had expected the Tesla to charge faster (on a percentage per hour basis), by virtue of the battery being smaller.

However, the opposite is true. I'd noticed that it seemed to be taking a long time to charge the car, but hadn't really paid proper attention to it, until this morning. Last night my car started charging at 12:30am at 56% and finished at 05:44am at 80%.

I have cheap electricity from 12:30am to 04:30am for charging my car, and thought the car would easily charge 24% in 4 hours, but apparently not!

Why is it taking so long to charge?! The Jag reliably charged at around 9% per hour, so would have done that in under 3 hours, despite having a much bigger battery.

Could it be because the car is still so new? My car still only has 324 miles on it, so doesn't have many cycles on the battery yet. That said, charging at 7kw isn't exactly fast, so I wouldn't have thought there was a need to throttle it! I bet if I went and plugged into a supercharger it would happy deliver way more than that.

Or could it be a settings issue in my car that needs adjusting?

Help!
 

vsansal

Member
Oct 11, 2019
77
41
Arlington,VA
Did you have anything running in your model 3? Like the sentry mode? Also I belive the jag has a usable battery of 85kWh battery brand new and a brand new model 3 long range should be between 77-78kWh. If you had some degredation on your jags battery, there isn't that much of a difference between them.
 

dhrivnak

Active Member
Jan 8, 2011
4,417
3,577
NE Tennessee
Check the charge rate as are you charging at a full 32 amps? Yesterday my car was slow and for some reason the charge rare was set to 5 amps. Strange but now I am set back to a faster rate.
 
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swaltner

Active Member
Oct 13, 2012
1,597
1,597
Kansas, USA
Did you in some way leave/have the heat on? That would make it pretty slow. When I am pre-conditioning the car it really pulls the charge speed down. Check the charge rate on the screen.

Make that, check the charge rate on the app. If you open the door to look at the screen, the HVAC turns on, unless you turn it back off, which will slow down the charge session.

Start a charge session during the day, or stay up late on night to your 12:30 AM charging session, let it charge for 15 minutes to let everything stabilize and then report back on the charging status on your phone app. We want to know what the mi/hr (edit: make that km/hr), volts, and amps readings are.
 

RJUK

Member
May 31, 2019
58
8
United Kingdom
Did you have anything running in your model 3? Like the sentry mode? Also I belive the jag has a usable battery of 85kWh battery brand new and a brand new model 3 long range should be between 77-78kWh. If you had some degredation on your jags battery, there isn't that much of a difference between them.
No, sentry mode is not set to be on at home. Nothing else on. Car was locked. Also the Jag had only 3500miles on it when it went back, so I doubt there was much battery degradation. Either way, the Tesla should be managing a minimum of 9% an hour the same as the Jag, not charging far slower. I actually expected 10%+ per hour.

I agree, you should be charging faster.
Maybe you left climate on ?
Is the t light flashing green near the charging port ?
The light was blue I think, because it was using timed charging.

Check the charge rate as are you charging at a full 32 amps? Yesterday my car was slow and for some reason the charge rare was set to 5 amps. Strange but now I am set back to a faster rate.
I think I need to do this. Might do a short 5 minute charge during the day at the weekend to check the settings or something. As long as a short charge isn't detrimental?

If you have a UMC and are using that to charge make sure it’s completely plugged into the plug.
UMC?

You are only charging at 30A if you are using 14-50 or 6-50 adapters. Others will be at 24A or less. Which adapter are you using?
I'm not using an adapter as such - cars in the UK come with a type 2 socket on the car and my home charger has a type 2 connector. It's a 7kw charger.

Did you in some way leave/have the heat on? That would make it pretty slow. When I am pre-conditioning the car it really pulls the charge speed down. Check the charge rate on the screen.
Not that I'm aware of. I got home, got out of the car and walked away as normal, leaving it to self-lock. Then walked out later, hit the "open charge port" button on my phone and plugged it in. Didn't even unlock the car to activate anything.

Make that, check the charge rate on the app. If you open the door to look at the screen, the HVAC turns on, unless you turn it back off, which will slow down the charge session.

Start a charge session during the day, or stay up late on night to your 12:30 AM charging session, let it charge for 15 minutes to let everything stabilize and then report back on the charging status on your phone app. We want to know what the mi/hr (edit: make that km/hr), volts, and amps readings are.

I may try this at the weekend.

One other thing. When my car starts charging, it makes a really weird noise from under the trunk. I guess it's cooling related stuff being fired up, as the Jag did the same when charging began, but the Tesla noise sounds a bit funky. Is anyone else getting the same? I'm hoping it's a normal noise that all cars make. I took a video of it. Can I post YouTube links here?
 

srs5694

Active Member
Jan 15, 2019
1,024
1,148
Woonsocket, RI
You are only charging at 30A if you are using 14-50 or 6-50 adapters. Others will be at 24A or less. Which adapter are you using?

@RJUK's location is listed as "United Kingdom." I don't know a lot about home EV charging in the UK, but they definitely do not use NEMA 14-50 or NEMA 6-50 outlets there.


UMC = Universal Mobile Connector -- that is, the charging box and cable that comes with the Tesla, and goes between the car's charge port and the wall outlet, at least in the US. I don't know offhand what comes with Teslas sold in the UK. When I go to Tesla's UK shop site, I don't see any mention of the UMC, just the Wall Connector.

To better diagnose the problem, I have two suggestions:
  • Check the charge rate in the car or on your app -- The car's display shows the charge rate, if the display is active; and you can get the same information via the Tesla app. For instance, for me, when I'm charging at home, it shows 32A and ~240v. As I'm in the US, this is single-phase. Some European countries support 3-phase power, which adds a twist. I believe that Tesla denotes this with a little "3" in a circle somewhere, so make note of that if you see it. The display will also show an estimated time to completion and a charge rate in miles (or kilometers) per hour.
  • Use a Tesla monitoring app or site -- Something like TeslaFi and some third-party apps can provide more detailed information on charging sessions. For instance, at this time of year, I often see charging sessions beginning with a low current draw and very little power going into the battery, as the car is using the electricity to heat the battery to a level where it can be more effectively charged. After 10-30 minutes, the charge rate goes up, presumably because the battery is sufficiently warm. Information like this might help you identify the source of the problem.
Others have posted some guesses about what may be wrong, but solid data on charge rate in volts and amps will help rule out some possibilities. As just noted, ambient temperature (and the temperature of the battery pack) may be an issue, too.
 

RJUK

Member
May 31, 2019
58
8
United Kingdom
@RJUK's location is listed as "United Kingdom." I don't know a lot about home EV charging in the UK, but they definitely do not use NEMA 14-50 or NEMA 6-50 outlets there.



UMC = Universal Mobile Connector -- that is, the charging box and cable that comes with the Tesla, and goes between the car's charge port and the wall outlet, at least in the US. I don't know offhand what comes with Teslas sold in the UK. When I go to Tesla's UK shop site, I don't see any mention of the UMC, just the Wall Connector.

To better diagnose the problem, I have two suggestions:
  • Check the charge rate in the car or on your app -- The car's display shows the charge rate, if the display is active; and you can get the same information via the Tesla app. For instance, for me, when I'm charging at home, it shows 32A and ~240v. As I'm in the US, this is single-phase. Some European countries support 3-phase power, which adds a twist. I believe that Tesla denotes this with a little "3" in a circle somewhere, so make note of that if you see it. The display will also show an estimated time to completion and a charge rate in miles (or kilometers) per hour.
  • Use a Tesla monitoring app or site -- Something like TeslaFi and some third-party apps can provide more detailed information on charging sessions. For instance, at this time of year, I often see charging sessions beginning with a low current draw and very little power going into the battery, as the car is using the electricity to heat the battery to a level where it can be more effectively charged. After 10-30 minutes, the charge rate goes up, presumably because the battery is sufficiently warm. Information like this might help you identify the source of the problem.
Others have posted some guesses about what may be wrong, but solid data on charge rate in volts and amps will help rule out some possibilities. As just noted, ambient temperature (and the temperature of the battery pack) may be an issue, too.
Thanks. My home charger is single phase only, not 3 phase.

Also, it's cold here, but not that cold. It was probably around 6 - 8c overnight last night, so fairly warm for this time of year. (That's 6 to 8 centigrade, not minus 8, BTW.) Again, comparable temps to what the Jag was charging in, if not warmer. And in the 5+ hours it was charging the car had plenty of time to heat the battery up to increase the charge speed sufficiently.

I suspect it's somehow set really low for some odd reason.
 

srs5694

Active Member
Jan 15, 2019
1,024
1,148
Woonsocket, RI
Also, it's cold here, but not that cold. It was probably around 6 - 8c overnight last night, so fairly warm for this time of year. (That's 6 to 8 centigrade, not minus 8, BTW.) Again, comparable temps to what the Jag was charging in, if not warmer. And in the 5+ hours it was charging the car had plenty of time to heat the battery up to increase the charge speed sufficiently.

6C is cold enough that there might be some slight effects from warming the battery. Remember that any two automakers (or even two models from one automaker) may do things slightly differently. Battery chemistries differ, and the judgments of the engineers who design and program the battery management systems also differ. Tesla might be insisting on warming batteries to slightly higher temperatures than Jaguar does, hence producing the difference you're seeing.

That's very speculative, though. As I said, you need hard data on the charge rate in volts and amps, and in miles/kilometers per hour, from the Tesla's screen or app. If it is a temperature effect, then this will start low but rise after a few minutes. It could be something else, though, like the Tesla detecting a fault in the wiring and therefore lowering the amperage (the car should issue an explicit warning about this), a defective charger in the car (the Model 3 LR has three, each of which provides 1/3 of the charging capacity), etc.
 

hcdavis3

HCD3
Mar 3, 2019
1,836
1,069
02571
No, sentry mode is not set to be on at home. Nothing else on. Car was locked. Also the Jag had only 3500miles on it when it went back, so I doubt there was much battery degradation. Either way, the Tesla should be managing a minimum of 9% an hour the same as the Jag, not charging far slower. I actually expected 10%+ per hour.


The light was blue I think, because it was using timed charging.


I think I need to do this. Might do a short 5 minute charge during the day at the weekend to check the settings or something. As long as a short charge isn't detrimental?


UMC?


I'm not using an adapter as such - cars in the UK come with a type 2 socket on the car and my home charger has a type 2 connector. It's a 7kw charger.


Not that I'm aware of. I got home, got out of the car and walked away as normal, leaving it to self-lock. Then walked out later, hit the "open charge port" button on my phone and plugged it in. Didn't even unlock the car to activate anything.



I may try this at the weekend.

One other thing. When my car starts charging, it makes a really weird noise from under the trunk. I guess it's cooling related stuff being fired up, as the Jag did the same when charging began, but the Tesla noise sounds a bit funky. Is anyone else getting the same? I'm hoping it's a normal noise that all cars make. I took a video of it. Can I post YouTube links here?
Universal mobile connector that came with the car.
 
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ewoodrick

Well-Known Member
Apr 13, 2018
5,285
3,725
Buford, GA
Hi folks, I've not long moved from a Jaguar I-Pace to a Model 3 Performance, and I have a 7kw home charger. The I-Pace had a 90kWh battery and the Tesla a 75kWh battery, so I had expected the Tesla to charge faster (on a percentage per hour basis), by virtue of the battery being smaller.

However, the opposite is true. I'd noticed that it seemed to be taking a long time to charge the car, but hadn't really paid proper attention to it, until this morning. Last night my car started charging at 12:30am at 56% and finished at 05:44am at 80%.

I have cheap electricity from 12:30am to 04:30am for charging my car, and thought the car would easily charge 24% in 4 hours, but apparently not!

Why is it taking so long to charge?! The Jag reliably charged at around 9% per hour, so would have done that in under 3 hours, despite having a much bigger battery.

Could it be because the car is still so new? My car still only has 324 miles on it, so doesn't have many cycles on the battery yet. That said, charging at 7kw isn't exactly fast, so I wouldn't have thought there was a need to throttle it! I bet if I went and plugged into a supercharger it would happy deliver way more than that.

Or could it be a settings issue in my car that needs adjusting?

Help!

When you plug in, you should see the charging screen appear on the monitor. On the bottom line, the voltage, current and charge time is listed. What is it saying?
 

derotam

Member
Oct 31, 2018
825
697
Oak Hill, VA
The light was blue I think, because it was using timed charging.

One other thing. When my car starts charging, it makes a really weird noise from under the trunk.

Ok, so I I have a theory... You are using scheduled departure right, possibly with cabin preconditioning? If you are then the car is turning on the battery preconditioning feature to help warm the battery in an attempt to reduce any cold induced limited regen.

The noise you are hearing under the trunk is power being applied to the motor to create the heat, to warm up the coolant, to warm the battery. Battery preconditioning can use up to ~7kW split between the motors. It sounds like your car is deciding to only push power to the rear motor for preconditioning(up to ~3.5kW)

Even if you are NOT using scheduled departure, this still could be the issue.

Can you take a picture of your charging screen and post it for us to see. This can answer all kinds of questions for us very easily.
 

SoManyM3s

Member
Apr 21, 2019
312
225
28262
At about 6-8 C, it’s not the battery preheating, that’s costing you. Even around freezing, and using my 120V charger, I barely lose about 10 minutes of charging time. There’s something else going on here. Just plug it in during the day and see what charge rate it’s giving you, it’s not gonna hurt your battery.
 

user212_nr

Active Member
Aug 26, 2019
1,407
741
US
I'm not using an adapter as such - cars in the UK come with a type 2 socket on the car and my home charger has a type 2 connector. It's a 7kw charger.

We are used to, on this forum, dealing with the specifics of the electrical system used for the charger. This includes the breaker size and the brand of the charger, as well as the voltage (UK is 230V, so implied here), and the plug.

Most of us are in North America (and even your EU friends will be on different systems), so you will especially need to provide the full details. Pictures of the charger and breaker box are even better.

The best that you will get is 10.7 hours or 3 hours for 25% as you are expecting, but in order to figure out what is wrong the details are needed. It would seem that the car is not properly recognizing the power of the charger. One use asked for a photo of the Tesla charging screen, and this would be very important.
 
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Rocky_H

Well-Known Member
Feb 19, 2015
6,131
7,138
Boise, ID
One use asked for a photo of the Tesla charging screen, and this would be very important.
@RJUK We need some more informative numbers to figure out anything with this. Quoting fill rates in % of battery per hour for two different sized batteries isn't very informative. And saying your wall charging unit has a total rated capacity of 7kW still doesn't say anything about what amount of that power each of the two cars are actually requesting/using. Get some real data of what the volts and amps really are when the car is charging. You can check that from the screen in the car, but do turn off the interior heating when you're going to check that, because that will siphon off some of that incoming power and will make your charging rate appear lower.
 

jmcr

Member
Jan 31, 2020
5
1
Hollywood, MD
It's just your charger limitations and losses through adapters. Spouse's Model 3 charges at 48 amps with Tesla Wall Charger which is about 1.5 your rate. Did so new, does so now with ~6K on it. (48a x 240v >11 Kwh). 40% the purchase and install cost of Wall Adapter was rebated by our state (MD).
 
Oct 31, 2019
244
312
Georgia
I think your amperage is simply set lower than what it should be. 7kW is about 30A at 240V.

See screenshot below:
  1. Go to your charging screen by pressing the lightning icon (Red circle).
  2. Report back what the amperage setting is showing (Blue circle).
7F30336D-C155-417B-8594-44E83BC982CC.jpeg
 

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