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2013 Model S dual charger charging @ 60amps vs 80amps

Pipcecil

Member
Feb 21, 2017
129
82
Midlothian, TX
I have been having a bit of a struggle trying to correct this issue and want some opinions or anything else come with this problem. I have had the car over 3 years (got used) and this is the first summer this has happened. And, where I live, the summer has been milder than previous summers, so my first jump of "heat" isn't the whole issue as the car would have had problems the prior summers). Note, car charges in garage with another EV (Bolt). There is a bit of history, so get ready:
  • First part of summer noticed car charging only @ 60 amps. A flip of the breaker and reset of the HPWC fixed the issue, but would go back once a week or so. Noticed at one point in the morning the car's fans (which are usually jet engine loud) were still running in the morning. Got a warning in car that AC cooling reduced to cool battery systems. I took the car into the shop (AC was blowing hot air) and it was determined that the active louvers were not opening, this was fixed
  • While car was being repaired, loaner P85 fans in same hot garage are whisper quiet and car never charged under 80amps. I expected this to occur with my car's fix.
  • Car still sounds like a jet engine much louder than the 2014 P85, 60amp reduction occurred one week after fix. Called tesla again and they thought it was the HPWC and sent mobile service. Up until then, having to reset the HPWC once every other day at least
  • Tesla tech comes out and says the car is receiving an "overcurrent" communication from the HPWC so it reduces the amps to 60. He then explains that is just fine and 60 amps is good and I should live with it. I pointed out I don't want to live with something that is not performing as advertised, something is wrong. They can't fix anything because its coming before the HPWC he said (electrical work).
  • Call electricians (overcurrent could create heat problems = fire, so want to make sure all is safe). Lines between the panel and HPWC seemed to be ok/working order. The main panel had some heat damage to the bus bars and electrician says if there is overcurrent, the car is probably the only smart one to detect it. Because of the damage, recommended replacing main breaker/bus bar, it wasn't a dire problem yet, but it will be eventually
  • While waiting for the items, sometimes (but not all the time) the HPWC shows a blinking yellow/orange light while charging or when finished charging (still green for both so it shows both).
  • Replacement for panel goes fine, but car reverts back to 60 amps (with blinking orange on HPWC) one day after.
  • Contact support via email asking what the blinking orange is, and was told it is a heating issue and might have bad connections in the HPWC.
  • Opened HPWC today to look at the connection bar thingie (sorry not an electrician). All wires were set in tight, no heat damage shown, reconnected wires just in case.
Now I am at a loss at what is wrong and how to fix it. Tesla assures me its not the car (does everyones car sound like a jet engine even when charging for a few minutes?). There is a heat problem somewhere, but I don't know from what. If its overcurrent it could be the electrical provider, but that seems less likely since it only happens now and not at other times. If it was just heat in general this should have happened years ok so blaming the weather won't work either. Is my HPWC bad? Could the car be interpreting things wrong? Is my wiring messed up? When I am charging I do notice some things that are hot:
  • Handle is very warm, almost uncomfortable to the touch, I would say equal to (and maybe more) than a supercharger when charging.
  • Breaker (100amp) directly to the car gets extremely warm, breaker to subpanel does NOT get that warm (cars on on subpanel), main breakers get extremely warm (just slightly less than the 100amp for the car).
Anyone have ideas? Should I go back and have Tesla look at it. I am still under the used car warranty for my vehicle for 7k more miles so anything will be free, but it won't soon. Anyone else have this occur? I am very perplexed.
 

MorrisonHiker

S 100D 2021.4.15
Mar 8, 2015
9,582
8,794
Colorado
Besides the amps, what volts are displayed? If your voltage is too low (or too high), the car will reduce the amps by 25% as a safety precaution. It would give a better picture if you can tell us what the voltage is when you are only charging at 60 amps.

When charging our cars in the early morning, our amperage is often reduced when our neighbor's pool pump is operating. If we charge at other times, we don't have an issue since we get closer to 240 volts. We reached out to our utility company but they said that the voltage was "within limits".
 
Last edited:

PWlakewood

Active Member
Jan 9, 2019
1,717
879
US
Have you rebooted the car? What software are you on? Do you know of anyone who has a similar setup so you can make sure its not the car? What gauge wire is used from the panel to hpwc? Do you have 200 amp service? If the handle is getting hot then that could be a sign of where the problem is. Either the handle or port on the car could have a loose fitment.
 

Pipcecil

Member
Feb 21, 2017
129
82
Midlothian, TX
Both @ 80 and 60 amps I get between 240-250 volts.

Rebooted the car numerous times. I am not on 10, but on the latest one before that one (can't remember the build)

I am unsure the wire, its either THHN or THWN and I believe 2 gauge (I did not install). The thickness looks the same as the wires for the unit and the electrician that came out last month inspected the wires used and said it was setup fine (from the subpanel)

I have 200 amp service for the house.

Yes the handle always gets hot. I don't recall if it was always that way or if its new(er) I am inclined to say this is new(er). Debris in the connector or car charge port cause things like this? I am pretty careful with my charging cable but I have dropped the handle on the concrete a few times
 

markb1

Active Member
Feb 17, 2012
3,038
652
San Diego, CA
Considering the loaner worked fine, I think there's still some sort of problem with your car.

If it's truly drawing more current that the 80A (or 60A) it says it's drawing, that would be a problem with the on board charger. (But I've never heard of that happening.) What your electrician is saying doesn't really make sense, because current is pulled by the charger, not pushed by the grid (or anything else). If your 200A panel or the wiring between the panel and wall connector isn't up to the job of supplying 80A, that's a problem for an electrician. But the loaner working fine suggest it's the car not the wiring (or in addition to the wiring, perhaps).
 
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AmpedRealtor

Well-Known Member
Jun 30, 2013
6,373
3,361
Phoenix, AZ
I have a 2013 P85 and have been dealing with this issue for 2 years on and off. Tesla provided me the following information from my logs:

5/19/2018 3:09:26 PM – voltage spike of approx. 35 volts
5/9/2018 4:36:06 PM – voltage spike of approx. 45 volts
5/9/2018 4:32:03 PM -- voltage spike of approx. 51 volts
5/9/2018 3:00:16 PM – voltage spike of approx. 33 volts
5/9/2018 1:36:49 PM – voltage spike of approx. 57 volts

Tesla said it was my HPWC and they replaced it with a next-gen wall charger. I still have the problems. Interestingly, the problems only seem to occur when the weather heats up. I live in Arizona and the problems manifest late spring through early fall. No issues during the winter time when temps are low and nobody is running their ACs. I had power company come out and they said service to the house checks out. My wall charger is literally on the other side of the wall from the panel, the run is like 3 feet. Had an electrician look things over, he said everything checks out just fine.

I told Tesla, how can the HPWC be causing voltage spikes? Makes no sense. They had no answer to that. A year later, when I told them the issues persisted, they refused to even discuss it with me and seemed annoyed. They said the vehicle does not cause voltage spikes, that those are originating from outside the car. They refused to tell me if the above spikes were AC or DC, and then told me they will no longer provide me with information from my logs.

I had no issues for the first four years of ownership and everything worked as it should. I don't understand why this is happening or why Tesla has completely shut me down.

Tesla has been screwing with the battery cooling and charge taper on older 85 kWh vehicles, as well as capping the battery's ability to charge due to safety concerns that they will not disclose. This thread may be of interest to you:

Sudden Loss Of Range With 2019.16.x Software
 

murphyS90D

Member
Jul 2, 2016
647
457
Horsham, PA
Were the wires into the HPWC installed with ferrules? It is very hard to get all of the strands clamped if ferrules are not used. One missed strand means that connection becomes a source of heat. I used 2 gauge wire because my panel is 75 feet from the garage. My wires only get slightly warm when 80 amps is flowing.
 

Pipcecil

Member
Feb 21, 2017
129
82
Midlothian, TX
@AmpedRealtor - it seems we are having the same problem. I have a next gen HPWC (I got it when the second gens first came out). My wall charger is maybe 8 feet from the subpanel on the same wall in the garage. I haven't had any issues prior to now. And, from what was mentioned in the new software from the battery fire response (most likely), it may be some new software that isn't allowing the car to heat up as much as it was, limiting the charging rate. I am almost inclined to believe that.

I don't understand how overcurrent could be occurring in my house in general. If it was the main breaker, that replacement should have fixed it. Also I should have had breakers trip every once in awhile. It may just be the software being more conservative. I mean I do run high on volts (usually around 250) so even a smaller spike could cause the car to protect itself. Hmmm...It just may be I have to deal with this reality now. I don't feel like buying a new HPWC considering what I spent to replace the main breaker, especially considering that could be a non-issue. Granted I did have the loaner for only a couple of days. I could have been lucky that there wasn't enough heat to trip the system. But I wonder, just in general, if my car just doesn't cool very efficiently and maybe those systems improved in 2014.
 

Pipcecil

Member
Feb 21, 2017
129
82
Midlothian, TX
Were the wires into the HPWC installed with ferrules? It is very hard to get all of the strands clamped if ferrules are not used. One missed strand means that connection becomes a source of heat. I used 2 gauge wire because my panel is 75 feet from the garage. My wires only get slightly warm when 80 amps is flowing.

Ferrules were definitely not used. it was the bare twisted mass of wire. Would this make a difference for the stranded wires? I always thought as long its its in that connector thingie all the way it works fine.
 

markb1

Active Member
Feb 17, 2012
3,038
652
San Diego, CA
I have a 2013 P85 and have been dealing with this issue for 2 years on and off. Tesla provided me the following information from my logs:

5/19/2018 3:09:26 PM – voltage spike of approx. 35 volts
5/9/2018 4:36:06 PM – voltage spike of approx. 45 volts
5/9/2018 4:32:03 PM -- voltage spike of approx. 51 volts
5/9/2018 3:00:16 PM – voltage spike of approx. 33 volts
5/9/2018 1:36:49 PM – voltage spike of approx. 57 volts

Tesla said it was my HPWC and they replaced it with a next-gen wall charger. I still have the problems. Interestingly, the problems only seem to occur when the weather heats up. I live in Arizona and the problems manifest late spring through early fall. No issues during the winter time when temps are low and nobody is running their ACs. I had power company come out and they said service to the house checks out. My wall charger is literally on the other side of the wall from the panel, the run is like 3 feet. Had an electrician look things over, he said everything checks out just fine.

I told Tesla, how can the HPWC be causing voltage spikes? Makes no sense. They had no answer to that. A year later, when I told them the issues persisted, they refused to even discuss it with me and seemed annoyed. They said the vehicle does not cause voltage spikes, that those are originating from outside the car. They refused to tell me if the above spikes were AC or DC, and then told me they will no longer provide me with information from my logs.

I had no issues for the first four years of ownership and everything worked as it should. I don't understand why this is happening or why Tesla has completely shut me down.

Tesla has been screwing with the battery cooling and charge taper on older 85 kWh vehicles, as well as capping the battery's ability to charge due to safety concerns that they will not disclose. This thread may be of interest to you:

Sudden Loss Of Range With 2019.16.x Software

It's disappointing to hear that Tesla is being so unhelpful. If the voltage spikes were on the AC side, something is very wrong on the utility's end! I'd bet either the voltage spikes are on the DC side or they misinterpreted the logs and gave you bogus information! Since they blamed the HPWC, it leads me to believe they had no idea what they were talking about!
 

murphyS90D

Member
Jul 2, 2016
647
457
Horsham, PA
The wire strand has to be tightly clamped to make a good connection. If a strand gets missed, even if it is in contact, it is a high resistance connection that will heat. The instructions for the HPWC mention ferrules but doesn't demand that they be used.
 

AmpedRealtor

Well-Known Member
Jun 30, 2013
6,373
3,361
Phoenix, AZ
It's disappointing to hear that Tesla is being so unhelpful. If the voltage spikes were on the AC side, something is very wrong on the utility's end! I'd bet either the voltage spikes are on the DC side or they misinterpreted the logs and gave you bogus information! Since they blamed the HPWC, it leads me to believe they had no idea what they were talking about!
That is my belief as well. Utility told me those are rather high spikes that would affect my entire house—computers, appliances, TVs, etc. I have no issues with any of those. The lines into my wall charger don't have ferrules on them, but they worked fine for four years. My voltage does sag from about 245v to 232-235v at 80A. Voltage sag is less in the morning than in the evening. I also have a grid-tied solar array all running through the same panel. Solar company said it's not them. Everyone says it's not them! Grrrr...
 

markb1

Active Member
Feb 17, 2012
3,038
652
San Diego, CA
That is my belief as well. Utility told me those are rather high spikes that would affect my entire house—computers, appliances, TVs, etc. I have no issues with any of those. The lines into my wall charger don't have ferrules on them, but they worked fine for four years. My voltage does sag from about 245v to 232-235v at 80A. Voltage sag is less in the morning than in the evening. I also have a grid-tied solar array all running through the same panel. Solar company said it's not them. Everyone says it's not them! Grrrr...

If you wanted to put some time/money into it, you could prove there's nothing wrong with your house power with some sort of voltage logger. You could also log the battery voltage over the CAN bus. But even with proof, I'm not sure Tesla would do anything!
 

ShawnA

Supporting Member
Nov 13, 2017
925
674
Edwardsburg, MI
Hi Pipcecil,

Some questions for you:
Was it ever determined what caused the heat damage in the main panel???
How many breakers or breaker positions are in your main panel???
You said above it is a 200 Amp service - What is the breaker size to the car's sub-panel?
You said above it is a 100 Amp breaker in the sub-panel for the car -
How many breakers or breaker positions in the car's sub-panel???
The 2 gauge wire from the main to the sub-panel - Is it copper or aluminum???

Sorry for the twenty questions, but with heat damage to the main panel, at some
time there was an excess draw of current.
I ask of the breaker count because it gives a size - heat sink dimension to the panel.
It would seem that your larger main panel would have a greater volume of metal bus
to dissipate the heat.
The sub-panel being smaller may generate the same heat as the larger panel
but not have the volume of bus metal to dissipate or spread it over...

If there are aluminum wires from the main to the sub-panel, even if they are the same
gauge as copper ones, they are rated to carry 77% of the load for copper wires.
They could be another source of heat or resistance...

Thank You,

Shawn
 

AmpedRealtor

Well-Known Member
Jun 30, 2013
6,373
3,361
Phoenix, AZ
If you wanted to put some time/money into it, you could prove there's nothing wrong with your house power with some sort of voltage logger. You could also log the battery voltage over the CAN bus. But even with proof, I'm not sure Tesla would do anything!
I expect it wouldn't matter. Tesla is in "warranty denial" mode with many owners right now, especially us old-timers. Seems like Musk has decided that we are dead weight.
 
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Pipcecil

Member
Feb 21, 2017
129
82
Midlothian, TX
Hi Pipcecil,

Some questions for you:
Was it ever determined what caused the heat damage in the main panel???
How many breakers or breaker positions are in your main panel???
You said above it is a 200 Amp service - What is the breaker size to the car's sub-panel?
You said above it is a 100 Amp breaker in the sub-panel for the car -
How many breakers or breaker positions in the car's sub-panel???
The 2 gauge wire from the main to the sub-panel - Is it copper or aluminum???

Sorry for the twenty questions, but with heat damage to the main panel, at some
time there was an excess draw of current.
I ask of the breaker count because it gives a size - heat sink dimension to the panel.
It would seem that your larger main panel would have a greater volume of metal bus
to dissipate the heat.
The sub-panel being smaller may generate the same heat as the larger panel
but not have the volume of bus metal to dissipate or spread it over...

If there are aluminum wires from the main to the sub-panel, even if they are the same
gauge as copper ones, they are rated to carry 77% of the load for copper wires.
They could be another source of heat or resistance...

Thank You,

Shawn

Hmmm lets see if I can answer the questions:
  • No, it was never determined what caused the heat damage on the main panel. It could be Texas Heat(tm) in a garage with 2 cars charging. But otherwise, it was of an undetermined nature
  • My main pain panel is completely full, its not a small one, nor is it a large one, so a middle size? sorry I can't give more info. We do run an extremely efficient house though. All LED lights, energy star everything like washer, dryer and fridge, induction range, heat pump water heater, etc. I seriously doubt we are spiking the 200amp house. The only thing that comes close is the induction range when its doing a cleaning cycle (probably ~40 amp pull, its on a 50 amp breaker). Main breaker never trips
  • 125 amp (largest you can get) from main panel to sub
  • yes the breaker to the HPWC is 100 amp to support the 80 amp twin chargers
  • Three active breakers in the subpanel, with like 5 more positions? The active ones provide to an 110 outlet (never used) and another EVSE for a chevy bolt (40 amp breaker)
  • I am assuming its stranded copper since its copper color and not silverish (assuming aluminum looks like that)
I was (and still am) concerned about the 125 amp breaker for the sub supplying the 80 amp tesla and 30 amp bolt. That seems like too much sustained power for the 125 amp breaker. But both electricians I had look at it said it wasn't an issue (both licensed). That said, the 125 amp breaker for the subpanel never heats up as much as the Tesla 100 or the main 200. Additionally these reduced amp charging has happened without the Bolt being charging and/or even being plugged in. I have had the subpanel breaker flip once when charging both vehicles over multiple hours, but it was only once.

Last time I charged the Tesla, I checked all the heat I could around the system (without obviously shocking myself or taking things apart. Here is where the heat ranked from hottest to least:
  • Cable right at the head - the cable feeding into the connector was SUPER hot. I would say "too hot to hold" after a second or so.
  • Connector head - hot, uncomfortable, but could manage holding on to it (almost too hot)
  • 100 amp breaker - quite warm
  • 200 amp breaker - quite warm but cooler than the 100 amp
  • 125 breaker - coolest of the 3
  • Remainder of the cable. The rest of the cable was cool. The farther from the connector head, the less heat there was. I don't use all the cable (barely maybe 10 feet of 25), so most stays wrapped up.
The extreme heat at the connector and the cable might be an even bigger clue. Are these supposed to get that hot? This was charging at a downgraded 60 amp for only 30 minutes.
 

ShawnA

Supporting Member
Nov 13, 2017
925
674
Edwardsburg, MI
Hi Pipcecil,

Thank you for answering my questions.
Generally the rule of thumb is that the breakers and wiring should operate at 80%
of their rating for optimum life, safety, and to avoid overheating.
Your 100 Amp breaker for the 80 Amp charging is right on the spot.
If your leaf actually pulls 30 Amps - the 40 Amp breaker is a good one...
When you do the math 125 Amp breaker at 80% is 100 Amps.
This answers conclusively that the 125 Amp breaker is NOT large enough to run
both the Tesla at 80 Amps and the Leaf at 30 Amps.
80 + 30 = 120 Amps 80% of what number is 120?
5/4 or 1.25 x 120 = 150 Amps
To operate both the Tesla and the Leaf at the same time at their maximum rated
amperage the breaker on the main panel to the sub panel should be 150 Amp.
You already stated that a larger breaker is not available...

Let me propose an alternative:
If you charge your Tesla at 70 Amps and the Volt at 30 Amps at the same time
that would total 100 Amps.
100 amps is 80% of 125 Amps which stays within the rating scheme.

My wife has a 2015 Dual Charger S.
Her High Power Wall Connector has a 100 Amp breaker so that she may charge at 80 Amps.
She has complained about the connector plugged into the car being too hot to handle.
I have changed her charging rate to either 70 or 72 Amps and she is happy it is cooler to handle.

We can speculate for a long time what may be going on in your system.
You can spend much more time and money tracking the situation.
My wife and I are happy charging her car at 70 or 72 Amps...

There are different ways to accomplish this - One is to set the rotary switch in the HPWC to
letter "C" which is for 72 Amps or Set the touchscreen in the car charging screen to 70 or 72 Amps.

There are many causes for overheated breakers - oxidation, poor connections, a strand of wire
not clamped into the breaker.
I once had an overheating breaker that would randomly trip. (100 Amp)
I could not tighten the screw any tighter on the breaker...
Closer inspection showed the the clamping screw was cross threaded...
I replaced the breaker and all has been quiet since then.

Please try 70 or 72 Amps. - I think you will like it...

Shawn
 

BrokerDon

Active Member
Aug 23, 2014
1,399
1,289
Newport Coast, CA
Our gen1 Tesla High Power Wall Connector ("HPWC") is on a 100A breaker. Charging at 80A we experienced:
  • Cable right at the head - the cable feeding into the connector was SUPER hot. I would say "too hot to hold" after a second or so.
  • Connector head - hot, uncomfortable, but could manage holding on to it (almost too hot)
  • HPWC face - warm... but not hot
  • 100 amp breaker - hardly warm
  • 200 amp breaker - cool
  • Remainder of the cable. The rest of the cable was cool. The farther from the connector head, the less heat there was. I don't use all the cable (barely maybe 10 feet of 25), so most stays wrapped up.
To get the longest life out of our HPWC I've lowered our 2015 P85D's charge rate from 80A to 60A in our Tesla's Settings and it runs significantly cooler. Cable right at the head and connector gets real warm but not HOT... and everything else are at slightly warm / normal temps.

When I drop to 40A, our HPWC runs MUCH cooler. The cable right at the head gets warm but everything else is ~ ambient temperature.

IMHO unless you need a QUICK charge, I'd avoid an 80A charge rate to lessen wear & tear on our HPWC cable head, cable and Tesla power socket. Charging even a fully depleted battery overnight is easy doable on 40A... or 60A if you want it faster. 80A charging simply isn't worth the HPWC risk or "wear" IMHO.
 

SoCal Buzz

Supporting Member
Oct 9, 2018
460
362
Orange County, CA, USA
@OP, while everyone would prefer to get max performance per spec levels, things do wear out over time. On my original 2013, the UMC sporadically failed or dropped the amperage over several months, until I had it replaced by Tesla. Of course, Tesla now limits the amps on newer models, so I cannot get max performance despite home wiring being up to the task. Anyway, I like the suggestion of @ShawnA of simply charging at 70 amps and not worrying about it. The parts in the car (I'm sure you've read about cars losing 1/2 of dual charger), HPWC and home will last longer and you won't have to invest more time in trying to diagnose.
 
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swegman

Active Member
Mar 27, 2012
1,580
1,619
I wired a 200 Amp panel in Florida with a Gen 1 HPWC located about 5 feet away. Wired with 4 gauge THWN-2 wire. 80 Amp breaker in the panel so 2013 P85 with dual chargers charge at 64 Amps.

The car charges at 64 Amps for hours without a hiccup. At 64 Amp current draw, car indicates voltage being 238-242 voltage, depending on time of day and what other devices are drawing power in the house. The house is about 3 years old.

The handle on the HPWC gets slightly warm after it’s been charging for hours but not enough to burn your hand or even to be uncomfortable. Same with the 80 Amp breaker; it gets warm but not dangerously hot. For comparison, the hot water from the sink is hotter than the HPWC handle or breaker.

I don’t not know why your HPWC handle gets so hot. But if your house voltage is 250 volts at times that could be kicking your charge current down. I would check with your power company whether 250 VAC is within their normal operating spec.

You could have two issues. Over-voltage plus high resistance in the HPWC handle (or charge port) that causes the heat issue. The car will kick down the charge current if it detects a High resistance leading to a temperature increase.
 
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