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Charge port & cable connector cleaning

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scaesare

Well-Known Member
Mar 14, 2013
10,799
25,163
NoVA
About a year after getting my S, I started to have issues with charge current reductions significantly more often than the occasional instance. This was often accompanied by a "charging problem" message on the dash. I also had the charge port go thru a lock/unlock/lock cycle 2 or 3 times after plugging in.

I brought it to Tesla's attention, and they looked at logs, but found no smoking gun. They suspected my early HPWC may be having issues, and because the design had been revised, had newer fuses, etc... they gave me a replacement. (awesome service, btw). As a test before swapping the new HPWC in, I cleaned my charge port and cable connector contacts with some electrical cleaner and a small industrial-style swab. (with breaker off).

Boom! Problem went away.

Fast forward to a couple of weeks ago... just about another year later. Once more charge current reduction issues several nights a week. The lock/unlock dance when inserting the cable. Last night the car failed to charge completely, and VisibleTesla reported "Disconnected" when the scheduled charge should have started. Inserting the cable today, and the car did the lock/unlock shuffle 3 or 4 times, and the port went red and the dash read "Check charge cable".

A couple of quick blasts of electrical cleaner, a couple of insertion/removal cycles to scrub the contacts a bit, and: Bingo! Connected without issue and happily charging for a few hours now.

I've just added charge port/cable cleaning to my annual maintenance when I also change my cabin air filter.
 
I really wish they would provide a kit to clean the connectors, it would save so many HPWC and UMC cable swaps.

Agreed, Some sort of cylindrical scrub brush for the power connectors, and perhaps most importantly something sized for the pilot signal contacts.

I believe flakey pilot signal connection is the issue, as that would explain the lock/unlock shuffle the car is doing... at that point only the pilot signal is active. It also may explain the current reduction,as I believe that the car will default to a lowest-common-denominator current value dependent on voltage, should it be having a difficulty reading the duty cycle of the signal...
 
Just curious wouldn't the service center do this as part of the annual inspection? Not every Tesla owner is proficient in contact cleaners, compatibility with plastic, abrasives, electrolysis, dielectric grease, etc.
 
Just curious wouldn't the service center do this as part of the annual inspection? Not every Tesla owner is proficient in contact cleaners, compatibility with plastic, abrasives, electrolysis, dielectric grease, etc.

There's a schedule floating around somewhere of what's done in an annual maintenance. I don't reacall connector cleaning being part of it, but I don't have it handy at the moment.

Based on what was there, I haven't felt the need to pony up the cash for an annual maintenance... I can check brake fluid, coolant, brake pads, change air filters, etc... myself.
 
Just curious wouldn't the service center do this as part of the annual inspection? Not every Tesla owner is proficient in contact cleaners, compatibility with plastic, abrasives, electrolysis, dielectric grease, etc.

They could do it with the UMC but not the HPWC, which remains at my home. I suppose they could consider it part of the valet service.
 
Agreed, Some sort of cylindrical scrub brush for the power connectors, and perhaps most importantly something sized for the pilot signal contacts.

I believe flakey pilot signal connection is the issue, as that would explain the lock/unlock shuffle the car is doing... at that point only the pilot signal is active. It also may explain the current reduction,as I believe that the car will default to a lowest-common-denominator current value dependent on voltage, should it be having a difficulty reading the duty cycle of the signal...

Those of you with Roadsters know that I make a Model S to Roadster adapter and I can't tell you how many problems I've seen with dirty connectors. I often get emails "My adapter used to work, now it's flaky and I get errors..." Then if they clean the contacts it starts working again. The worst one is ground.

If the pilot signal is flaky then it usually won't charge at all. In order to charge at the lowest rate with no pilot, the pilot has to be grounded. If the amps are reduced it's probably due to a poor ground connection or possibly one of the power pins.
 
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Those of you with Roadsters know that I make a Model S to Roadster adapter and I can't tell you how many problems I've seen with dirty connectors. I often get emails "My adapter used to work, now it's flaky and I get errors..." Then if they clean the contacts it starts working again. The worst one is ground.

If the pilot signal is flaky then it usually won't charge at all. In order to charge at the lowest rate with no pilot, the pilot has to be grounded. If the amps are reduced it's probably due to a poor ground connection or possibly one of the power pins.

Ahh.. makes sense. Thanks...
 
Tonight, my wife needed to unplug the car while it was charging, she called me out and said that the cable was really hot (normally we don't notice it because it's cooled off overnight). I grabbed two cotton swabs, made them slightly damp with water, and cleaned the high-power contacts. The contacts were hot as you could see steam coming off them while being cleaned.

The aftermath:
20150626_190840.jpg


Opportunity for a lot of resistance there.
 
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"I found the same thing but when I asked my Tesla SC about it, they said very emphatically NOT to use any kind of contact cleaner spray and only to use a can of compressed air."

Somebody at your SC is all wet. Air will not remove any kind of oxidation or oil/grease contamination. Deoxit or similar does the job.
 
Tesla doesn't use anything to clean the port or the UMC at the annual. I've had a lot of problems with UMCs and three charge ports and they advised me to use an air compressor nightly. Amazed by all the dirt and crap that comes out of both! I'm sure it's a hear thing as to why they aren't sealed but everything gets in there and then transfers to the UMC.

Recently i I was at the mall and they had brought in portable air compressors to blow out the HPWCs
 
Just did charge port maintenance on mine today. Have about 9 black Q-Tips to prove it. :)

Here's some interesting pics of my TED Pro (whole house electrical monitoring) and Visible Tesla, showing the voltage drop across dirty connectors vs. cleaned connectors.

TED Pro, not charging, before cleaning. System voltage 244 V at my home panel.

[01]TED-UL-BC.png



Visible Tesla, just before the charge starts, before cleaning. Car sensed voltage is 243 V.

[02]VT-UL-BC.png



TED Pro, charging at 80 A, before cleaning. System voltage 240 V (was actually bouncing between 240 and 241).

[03]TED-LD-BC.png



Visible Tesla, charging at 80 A, before cleaning. Car sensed voltage 238 V.

[04]VT-LD-BC.png



Power being dissipated in the HPWC handle = (241 - 238) * 80 = 240 W.



TED Pro, not charging, after cleaning. System voltage 243 V.

[05]TED-UL-AC.png



Visible Tesla, just prior to starting charge, after cleaning. Car sensed voltage 243 V.

[06]VT-UL-AC.png



TED Pro, charging at 80 A, after cleaning. System voltage 238 V.

[07]TED-LD-AC.png



Visible Tesla, charging at 80 A, after cleaning. Car sensed voltage 237 V.

[08]VT-LD-AC.png



Power being dissipated in the HPWC handle = (238 - 237) * 80 = 80 W.


Only 1/3 of the heat is being generated in the HPWC handle after cleaning the car's contacts as well as the HPWC contacts (with breaker off).

I was on vacation at the beach for a week, the salt air as well as the sand tends to dirty things up. I also have been using several superchargers lately, they get dirty because they're always outside, and they transfer the dirt to your charge port. That, in turn, transfers dirt to your HPWC and/or UMC.

Cleaning supplies:
Spray the DeoxIt on one of the brushes and clean all the contact surfaces. Then use the swabs to remove all the dirt and dry the contacts.
 
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I also have been using several superchargers lately, they get dirty because they're always outside, and they transfer the dirt to your charge port. That, in turn, transfers dirt to your HPWC and/or UMC.
Spray the DeoxIt on one of the brushes and clean all the contact surfaces. Then use the swabs to remove all the dirt and dry the contacts.
I noticed the dirt yesterday at the supercharger, planning to carry a compressed gas duster next time...can the DeoxIT be used for cleaning the supercharger connector???
 
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I noticed the dirt yesterday at the supercharger, planning to carry a compressed gas duster next time...can the DeoxIT be used for cleaning the supercharger connector???

My hesitation with that would be that there is no way for us to deenergize the Supercharger equipment to ensure that the connector is unpowered. It's never supposed to have power on it until the car negotiates the connection, but if something was wrong with the Supercharger, it's possible.

I would instead just use compressed air to get it as clean as possible, and if you notice a really dirty (or broken) connector, call the Tesla help line and report it.
 
Slightly off topic, but when I found the Tesla plug on the HPWC and UMC being a bit difficult to push into the car, I coated the exterior of each with Sailkote / McLube which is basically a teflon spray. The plug now slides smoothly in and out...

Based on the comments here I'll also use my air compressor to blow out all the connectors.
 
Power being dissipated in the HPWC handle = (241 - 238) * 80 = 240 W.

Power being dissipated in the HPWC handle = (238 - 237) * 80 = 80 W.

Well, that's the power dissipated across all the wiring, not just the HPWC handle/plug. Still if your plug is dissipating that much power continuously you will not be able to hold it, just picture an 80W incandescent bulb.

I would like to know if Tesla service cleans and inspects the UMC plug/car receptacle as part of regular maintenance visits as I have not seen that on the service summary.