Drawing 12A but charging only 1mph

[gabrielschulho]

Hey, all! I don't get it. My 12A/110V plain old wall socket charger normally charges at 5 - 6 mph. This morning I caught it going at 1 mph. What's going on?

 

[Sophias_dad]

Its heating the battery initially, or if you are actually sitting in the car when checking, its running the HVAC which will absorb pretty much all you can get from a 120V outlet.

 

[gabrielschulho]

Its heating the battery initially, or if you are actually sitting in the car when checking, its running the HVAC which will absorb pretty much all you can get from a 120V outlet.

Oh no, I found it like this in the morning. It was charging all night and I expected it to be long finished, but instead it was limping along at 1 mph. That's concerning because, if I can't rely on my own charger, my only option is to supercharge the whole time, qhich will dwgrade the battery prematurely.

 

[Sophias_dad]

Oh no, I found it like this in the morning. It was charging all night and I expected it to be long finished, but instead it was limping along at 1 mph. That's concerning because, if I can't rely on my own charger, my only option is to supercharge the whole time, qhich will dwgrade the battery prematurely.

I have no answer to that. Perhaps a door/trunk was left open causing the HVAC to run all night?

 

[GtiMart]

Yep, I agree, I would check that first. You can try to manually turn off the AC when you park the car, before charging, to see if it will charge faster. The fact that it's pulling 12A @ 117V means it's getting 1.4kW. The car is doing something with that energy, it's not going into the ether, the laws of conservation of energy are making sure of it Since it's mostly not going to the battery (1mph must be around 250w?), the most obvious culprit would be AC. I would say battery heating in general but since you're in SoCal, I don't think so.

 

[henderrj]

Oh no, I found it like this in the morning. It was charging all night and I expected it to be long finished, but instead it was limping along at 1 mph. That's concerning because, if I can't rely on my own charger, my only option is to supercharge the whole time, qhich will dwgrade the battery prematurely.

Supercharging will not age the battery in any significant way. I've got a Model S from 2014 with 250,000 miles on it and the original battery. It was supercharged a lot, albeit mostly with Urban superchargers. And of course they've really slowed down the supercharging on those old models. But your battery is the newer type and is very unlikely to have issues that way. I wouldn't worry about that part.

On the other hand, they're going to charge you for that! Even given the inefficiency of charging at 110 volts, it's still going to be a lot cheaper than you would pay to charge at a supercharger.

 

[hgmichna]

Supercharging will not age the battery in any significant way.

A little correction. If somebody drives hundreds of miles every day and always supercharges, it would age the battery significantly.

Fortunately that is very far from normal use for almost all of us. The battery degradation we have to cope with is calendar ageing.

Our batteries are quite long-lived though. If you want to keep them even longer, avoid high temperatures and high states of charge. LFP batteries are particularly resistant to nearly everything, so they are very nearly care-free.

If you really want to squeeze a few more years out of your battery, charge NMC batteries to 60% and LFP batteries to 70% whenever you don't need more.

Before a long drive, do charge to 100% though. Don't forget that the battery is there to serve your needs, not the other way around.

 

[henderrj]

I hardly think I'm the only person like this, but we supercharged once or twice a day three or four days a week, charging it to 100% many times throughout the life of the car. I've had it to zero miles more than a few times, my son has three times had to be flatbedded to a charger. I bought it with 38,000 miles on it and it currently has 254,000 mi on it. The vehicle is a 2014 December build, so not old, but not Young either. Still, as I said, the original battery pack. Although I'm on my third drive unit. One possible variable that is important, we lived in the Pacific Northwest for most of that time. So the temperature didn't vary greatly. Neither extremely cold or extremely hot hardly ever up there.

I think longevity depends greatly on the consistency of the cells within the pack. In any event, you are correct about one thing - use the car! That is why we bought them after all.

 

[AlanSubie4Life]

I don't get it. My 12A/110V plain old wall socket charger normally charges at 5 - 6 mph. This morning I caught it going at 1 mph.

Oh no, I found it like this in the morning. It was charging all night and I expected it to be long finished

You added 76 miles in this charging session which is consistent with 15 hours of charging at 5 rated miles per hour.

Doesn’t seem like a problem if this was just an overnight charge session. All is behaving as normal.

As others have mentioned, it is straightforward and normal to get extremely slow charging speeds like 1mph when the door is open when charging at 1.4kW. Not difficult to achieve at all, and certainly does not require battery heating.

 

[DianeD]

Hello! Did you ever solve this? We’ve recently bought our second tesla and it will only charge max at 12a. Using the same charger on the older car (2021) allows 32a. TIA

 

[jjrandorin]

I hardly think I'm the only person like this, but we supercharged once or twice a day three or four days a week, charging it to 100% many times throughout the life of the car. I've had it to zero miles more than a few times, my son has three times had to be flatbedded to a charger. I bought it with 38,000 miles on it and it currently has 254,000 mi on it. The vehicle is a 2014 December build, so not old, but not Young either. Still, as I said, the original battery pack. Although I'm on my third drive unit. One possible variable that is important, we lived in the Pacific Northwest for most of that time. So the temperature didn't vary greatly. Neither extremely cold or extremely hot hardly ever up there.

I think longevity depends greatly on the consistency of the cells within the pack. In any event, you are correct about one thing - use the car! That is why we bought them after all.

This is the model 3 subforum, which has a different battery than your model S. People report 4-5% degradation on model S, after several years, when on model 3s "normal" is morel ike 10-12% over the same time.

We all really dont know what the long term effects of supercharging the battery in a model 3 is, but I would say something we do know at this point is that model S degradation isnt really applicable to model 3/Ys.

 

[henderrj]

This is the model 3 subforum, which has a different battery than your model S. People report 4-5% degradation on model S, after several years, when on model 3s "normal" is morel ike 10-12% over the same time.

We all really dont know what the long term effects of supercharging the battery in a model 3 is, but I would say something we do know at this point is that model S degradation isnt really applicable to model 3/Ys.

That's fair. One just hopes that the newer technology would have better longevity.

 

[AlanSubie4Life]

That's fair. One just hopes that the newer technology would have better longevity.

It’s just really unclear how the display correlates with energy for Model S/X.

You may be able to find someone on the Model S forums who knows these answers:
1) What is the initial capacity of the vehicle?
2) At what capacity does the car start to display loss? How is this managed?
3) Does Tesla take any steps to disguise capacity loss?

I have never dug into it for older Model S but at least on some of the newer ones it seemed that the car could lose a couple kWh before it showed loss. This is somewhat similar to some Model 3 - but not all Model 3.

For example the 2018/2019 Model 3 could lose 2.5% capacity or so before showing any loss. However, this was not accomplished with a top buffer or a bottom buffer (in the traditional sense)! For recent Model 3, this is not so much the case - many show loss after just a fraction of a % capacity loss.

The other thing to keep in mind is that the BMS are different. Tesla may be more conservative for several years with Model 3 on the estimates. That could introduce a couple % difference. Just hard to know.