New Model 3 - sudden change in 110 charging speed

[Akkermonster]

I would like to get some input on a charging speed change I am suddenly seeing on my 2-week old M3 AWD long range. My first 4 charges using the mobile connector on a 110 outlet yielded a fairly remarkable and unexpected 5 miles per hour or charge. I thought it was great considering this fits our driving range and pattern. Two days ago it suddenly changed to a misly 2 miles per hour of charge. What happened?

The only thing I can think of that I did was to examine and adjust the charging section on the display (was trying to figure out the options and controls) - but I returned everything to the same state as before. My charging is set to max of 80% - I believe the same as it came with from the factory. Also, on my Tesla app, when charging now (after the charge speed change) it is showing "5/12A" on the right under the large green battery/range indicator. I don't recall what it said before...

Has anyone see this? What did I do wrong?

*Preempting any posts to tell me I should really spend the money on an 30A circuit and a wall charger - I am working on it. I just want to know how this works.

Thanks!

 

[Rocky_H]

Also, on my Tesla app, when charging now (after the charge speed change) it is showing "5/12A" on the right under the large green battery/range indicator. I don't recall what it said before...

You lowered it to 5 amps of current instead of the 12A it had before--pretty straightforward. That's not a setting you can change in the mobile app. You need to go on the car's screen, pull up the charging screen and press the up button on the amps to turn it back up to 12 while it's charging.

 

[ucmndd]

"5/12A" is the only relevant info here.

This means that your car is currently pulling 5 amps out of a maximum 12 on your NEMA 5-15 120 volt adapter.

Usually this happens because the car senses a voltage drop or other potential problems with the wiring and drops the amperage back as a safety precaution.

Are you using an extension cord or anything of the sort? Have you tried a different outlet?

You may need to start charging and then manually raise the amperage limit in the car back to 12. That said, if it automatically drops back down again, it's probably because there's something wrong with your wiring or other devices are using the same circuit.

Don't look a the "miles per hour" rating - the only thing that matters is volts and amps. What voltage does your car show when charging?

 

[timk225]

You don't have a 110 outlet, you have a 120 volt. That's what it's meant to be anyhow.

Search my recent posts, I just put 2 thoroughly excellent and short videos on YouTube showing how to put in a 6-20 and a 14-50. They aren't really for someone with zero electrical knowledge, but you'll see what has to happen.

 

[Akkermonster]

You lowered it to 5 amps of current instead of the 12A it had before--pretty straightforward. That's not a setting you can change in the mobile app. You need to go on the car's screen, pull up the charging screen and press the up button on the amps to turn it back up to 12 while it's charging.

Thanks Rocky_H - much appreciated. I will try this tonight. I suspect my looking/changing the charge settings caused this, although I don't recall specifically altering the amps.

 

[Akkermonster]

"5/12A" is the only relevant info here.

This means that your car is currently pulling 5 amps out of a maximum 12 on your NEMA 5-15 120 volt adapter.

Usually this happens because the car senses a voltage drop or other potential problems with the wiring and drops the amperage back as a safety precaution.

Are you using an extension cord or anything of the sort? Have you tried a different outlet?

You may need to start charging and then manually raise the amperage limit in the car back to 12. That said, if it automatically drops back down again, it's probably because there's something wrong with your wiring or other devices are using the same circuit.

Don't look a the "miles per hour" rating - the only thing that matters is volts and amps. What voltage does your car show when charging?

Thank you. No, no extension cord and I am using the same outlet. Will try to raise the amperage during the next charging session.

 

[F14Scott]

Also, there's a great, inexpensive charging solution you may not know about:

If your 120V outlet in the garage is a single (i.e. NOT daisy chained with other 120V outlets. It has to be the only outlet connected to the breaker.), then you can swap the single pole breaker for a double pole breaker at the same amperage and then have 240V pushing the same amperage to your car.

Assuming you are using a 15A circuit, now, you'll go from 4 to 5 MRPH to 11 MRPH. If the wiring in your wall happens to be yellow Romex (rated for 20A), you would go to 15 MRPH.

The new breaker would be about $100, a new outlet would be $25 (for a high quality one), and you'd need the new adapter for your mobile connector ($35). An electrician could do the work in about 15 minutes.

 

[Akkermonster]

You don't have a 110 outlet, you have a 120 volt. That's what it's meant to be anyhow.

Search my recent posts, I just put 2 thoroughly excellent and short videos on YouTube showing how to put in a 6-20 and a 14-50. They aren't really for someone with zero electrical knowledge, but you'll see what has to happen.

Didn't know - I guess it was 110 at some point and has been since changed to 120v. Thanks for the video references!

 

[Akkermonster]

Also, there's a great, inexpensive charging solution you may not know about:

If your 120V outlet in the garage is a single (i.e. NOT daisy chained with other 120V outlets. It has to be the only outlet connected to the breaker.), then you can swap the single pole breaker for a double pole breaker at the same amperage and then have 240V pushing the same amperage to your car.

Assuming you are using a 15A circuit, now, you'll go from 4 to 5 MRPH to 11 MRPH. If the wiring in your wall happens to be yellow Romex (rated for 20A), you would go to 15 MRPH.

The new breaker would be about $100, a new outlet would be $25 (for a high quality one), and you'd need the new adapter for your mobile connector ($35). An electrician could do the work in about 15 minutes.

I will share this with my electrician friend - he will know what to do! LOL Thanks!

 

[Polly Wog]

The car won't let you RAISE the amperage WHILE you are charging, so you need to set it the max of 12 amps BEFORE you actually start charging.

 

[ucmndd]

The car won't let you RAISE the amperage WHILE you are charging, so you need to set it the max of 12 amps BEFORE you actually start charging.

Hmm, model 3 thing? I can definitely do this in my S during an active session.

 

[GHammer]

Thanks Rocky_H - much appreciated. I will try this tonight. I suspect my looking/changing the charge settings caused this, although I don't recall specifically altering the amps.

Sometimes a voltage sag will cause the car to lower the amperage on it's own. The car remembers the lower amperage based on the location so all subsequent charges will be at the lower level until you go the car and manually readjust back up. This happens on one of my charge circuits that is on a sub-panel along with a heat pump.

 

[Rocky_H]

Sometimes a voltage sag will cause the car to lower the amperage on it's own.

Not to 5, though, which shows that it was manually turned down. It backs off to three fourths of what it was at if it's a wiring problem. I just saw another post recently where someone was fighting with charging from a crazy long wiring run in their condo building, and it had backed off from 12A to 9A because of that.

 

[ucmndd]

Not to 5, though, which shows that it was manually turned down. It backs off to three fourths of what it was at if it's a wiring problem. I just saw another post recently where someone was fighting with charging from a crazy long wiring run in their condo building, and it had backed off from 12A to 9A because of that.

Interesting, thanks.

I had a public L2 208/30a charger back off to 23A on me when the voltage sagged to ~190, and I thought that was a weird number. But indeed, it’s 75% of 30A (well 22.5 but rounding yadda yadda).

 

[Snow Drift]

I charge via a household plug (NEMA 5-15) in the garage, and we add 5 mph, @ 1 kW. We also use a 15' 15A 12/3 HD extension cord...

 

[Psghosh]

I would like to get some input on a charging speed change I am suddenly seeing on my 2-week old M3 AWD long range. My first 4 charges using the mobile connector on a 110 outlet yielded a fairly remarkable and unexpected 5 miles per hour or charge. I thought it was great considering this fits our driving range and pattern. Two days ago it suddenly changed to a misly 2 miles per hour of charge. What happened?

The only thing I can think of that I did was to examine and adjust the charging section on the display (was trying to figure out the options and controls) - but I returned everything to the same state as before. My charging is set to max of 80% - I believe the same as it came with from the factory. Also, on my Tesla app, when charging now (after the charge speed change) it is showing "5/12A" on the right under the large green battery/range indicator. I don't recall what it said before...

Has anyone see this? What did I do wrong?

*Preempting any posts to tell me I should really spend the money on an 30A circuit and a wall charger - I am working on it. I just want to know how this works.

Thanks!

I just saw this first-hand while at a vacation house. The car was in the sun and the AC had kicked on to keep the car under ~105 degrees. Also keep in mind that the gen2 portable connector can sense outlet plug temp and may also throttle down the speed if the temperature gets too high.

 

[gaswalla]

just fyi that some 3's have been randomly choosing 5amps as the default charge rate - there's a thread on that. Happened to me (but I charge at 240v), and just need to adjust the settings. When the car detects a potential fault, I would think it would drop the charge from 12amps to about 9 amps in OP's situation

 

[gaswalla]

here's that thread
Defaulting to 5 amps

 

[Akkermonster]

An update - I was able to raise amperage from 5A back to 12A (both before starting to charge and during the charging) and this put charging "speed" back to 5mi /hour. Has been working normally for the last 3 days. Thanks all for your feedback.

 

[Boomer543]

Glad it worked.