Charge port & cable connector cleaning

[SomeJoe7777]

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.

Yes, you're correct in that those numbers represent the total power dissipation over the entire wiring between the measurement points (one in my breaker panel with the TED meter, the other in the car at the battery terminals). However, we can assume that most of the resistance is at the connection points in the breaker, HPWC contacts, charge port, and charger HV box in the car.

My HPWC handle had been getting quite warm during charging sessions so I assume a fair amount of power was being dissipated at the charge port connector.

To my knowledge, I don't think that Tesla cleans the charge port during annual maintenance, and they absolutely should. However, that's only part of the maintenance that needs to be done. The HPWC, UMC, and Chademo adapters (if you own one) should also be cleaned, but UMC and Chademo may not be in the car, and HPWC certainly won't be.

 

[Moncton S85]

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.

Hi There

I have been having the exact same issue, assuming that salt from the roads here in Atlantic Canada is getting in the port... Where do I get "Electrical Cleaner"?

 

[SomeJoe7777]

Hi There

I have been having the exact same issue, assuming that salt from the roads here in Atlantic Canada is getting in the port... Where do I get "Electrical Cleaner"?

Amazon.com: DeoxIT® DN5 Spray, (NSN-6850-01-519-5548) 5% solution 163 g: Office Products

This is DeoxIT DN5S, a popular electrical contact cleaner, and is the one I use. This is a 6oz spray in the quick-dry, non-drip, non-flammable formulation.

You can also use the standard formulation, D5S:

Amazon.com: Hosa D5S-6 CAIG DeoxIT 5% Spray Contact Cleaner, 5 oz.: Musical Instruments

It's less expensive, but will take a bit longer to dry, and uses mineral spirits as the solvent, so it is flammable until it dries.

Spray either of these on a small brush or lint-free swab to clean all connectors.

 

[brucet999]

[QUOTE="

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).

[/QUOTE]

 

[brucet999]

I would suggest that your conclusion of 80W power loss due to a 1V difference in displayed measurements of 238V vs 237V may be iffy. Had the displays been 238.1V vs 237.1 V, I would have more confidence in the result. For all you know, you may actually have had a minuscule difference of 237.5V vs 237.4V, one rounded up to 238 and the other rounded down to 237 in the display. Of course, the actual numbers could also have been worse; 238.4V rounded down and 236.5V rounded up.

You do know that voltage measured on an open circuit is not "real" since line loss doesn't show up until the circuit is under load? That is why voltage measure 243 before charging but only 237V or 238V during charging.

 

[brucet999]

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:
View attachment 85397

Opportunity for a lot of resistance there.

FlasherZ, I wonder what you think about dirty contacts maybe causing SuperCharger problems I have had at three different stations of two different sites?
In all three instances, I have plugged in, seen the charge port light change from white to green and then after a few seconds to dark blue/purple. Charge rate remains zero and an error message appears on the car's screen "Cannot charge. Please disconnect and try again." Three to 5 re-connections produced the same result. Moving to another station solved the problem. In one case, I observed another Tesla plugged in at the problem station I had just left and it started charging with no problem.

Service Center has twice checked out my charge port and pronounced it fine and said that the SuperCharger stations must have been faulty.

Could this problem be as simple as dirty contacts on both my charge port and certain SC plugs?

You used damp Q-tips. What is your ideal contact cleaner, maybe isopropanol? Presumably nothing acidic.

 

[SomeJoe7777]

You do know that voltage measured on an open circuit is not "real" since line loss doesn't show up until the circuit is under load? That is why voltage measure 243 before charging but only 237V or 238V during charging.

Yes, of course, that's why my numbers were obtained with the car charging. Open-circuit voltage was 243V. During charging, system voltage in the panel dropped to 238, with 237 sensed at the car.

Even though the measurements have only 1V precision, it's clear that cleaning the contacts reduced the total voltage drop across the charging hardware and therefore the power dissipation.

 

[brucet999]

Yes, of course, that's why my numbers were obtained with the car charging. Open-circuit voltage was 243V. During charging, system voltage in the panel dropped to 238, with 237 sensed at the car.

Even though the measurements have only 1V precision, it's clear that cleaning the contacts reduced the total voltage drop across the charging hardware and therefore the power dissipation.

I'm confused. I can't find any reduction in voltage drop between before and after. What am I missing?

 

[scaesare]

Hi There

I have been having the exact same issue, assuming that salt from the roads here in Atlantic Canada is getting in the port... Where do I get "Electrical Cleaner"?

The stuff I use is CRC Electronic Cleaner

The recommendation by @SomeJoe7777 should be good too.

 

[FlatSix911]

Amazon.com: DeoxIT® DN5 Spray, (NSN-6850-01-519-5548) 5% solution 163 g: Office Products

This is DeoxIT DN5S, a popular electrical contact cleaner, and is the one I use. This is a 6oz spray in the quick-dry, non-drip, non-flammable formulation. You can also use the standard formulation, D5S:

Amazon.com: Hosa D5S-6 CAIG DeoxIT 5% Spray Contact Cleaner, 5 oz.: Musical Instruments

It's less expensive, but will take a bit longer to dry, and uses mineral spirits as the solvent, so it is flammable until it dries.
Spray either of these on a small brush or lint-free swab to clean all connectors.

The stuff I use is CRC Electronic Cleaner

The recommendation by @SomeJoe7777 should be good too.

Thanks for the recommendations ... how often do you clean the contacts? Both the plug and receptacle?

 

[mknox]

I have been having the exact same issue, assuming that salt from the roads here in Atlantic Canada is getting in the port... Where do I get "Electrical Cleaner"?

When I was having similar problems, I thought I would try an electrical contact cleaner myself. But since I live close to a Service Center, I figured I would drop by and ask them about this first. They were very adamant that I NOT use any sort of contact cleaner in the charge port or cable connectors under any circumstances. They were clearly a bit freaked out that I would even suggest it. They said the only thing I should use, and very carefully, is compressed air like those cans you get for blowing out computer keyboards.

 

[scaesare]

Thanks for the recommendations ... how often do you clean the contacts? Both the plug and receptacle?

I've been doing it once a year, or as needed... cabin air filter replacement and clean the contacts.

 

[scaesare]

When I was having similar problems, I thought I would try an electrical contact cleaner myself. But since I live close to a Service Center, I figured I would drop by and ask them about this first. They were very adamant that I NOT use any sort of contact cleaner in the charge port or cable connectors under any circumstances. They were clearly a bit freaked out that I would even suggest it. They said the only thing I should use, and very carefully, is compressed air like those cans you get for blowing out computer keyboards.

Yeah, I've heard that too.... but as of yet I've not heard of any reasoning behind it. The product I've selected is safe for plastics, electrical conductors, and insulating material. My feeling is that there is no official recommendation from Tesla on using any products in the cable/ports, and so the service techs are being conservative as they don't want folks spraying Lysol or WD-40 in their charge ports, and I don't blame them.

I can tell you this: the grime that comes out on the industrial swabs is NOT something that's going to get blown out by compressed air. It's a build-up on the surfaces that needs some solvents and mechanical scrubbing to remove...

I also have had the car for nearly 4 years now, and no degradation I've been able to determine.

 

[vdiv]

Tesla has been proactive in replacing the cords and plugs on the Supercharger stalls. Kudos to the folks doing it. Other public charging stations are not so lucky with ground faults becoming a common occurrence.
Wish there was a bit more emphasis on the home wall connector plug and car port maintenance as well. Perhaps some information sent to the owners or sessions held at the service centers would help.

 

[SomeJoe7777]

I'm confused. I can't find any reduction in voltage drop between before and after. What am I missing?

I'm measuring AC system voltage in two places. One is inside my circuit breaker panel, using the TED system. The other is at the car, using Visible Tesla. The voltage difference between these two will give the drop in voltage across the breaker, wiring to HPWC, HPWC contacts, HPWC charging cord, HPWC handle, and charge port.

In the before cleaning case, and before commencing charge, the voltage both at the panel and in the car was 243 volts (i.e. equal voltage everywhere, as would be expected with no current flow to the car). After commencing charge at 80A, then we had voltage in panel at 241V, voltage at car is 238V, or a 3V drop. 3V * 80A = 240W.

After cleaning the charge port and contacts, before commencing charge, the voltage both at the panel and in the car was 241 volts (again, equal voltage everywhere, as would be expected with no current flow to the car). After commending charge at 80A, then I had voltage in the panel at 238V, and voltage at the car of 237V, or now only a 1V drop. 1V * 80A = 80W.

 

[SomeJoe7777]

When I was having similar problems, I thought I would try an electrical contact cleaner myself. But since I live close to a Service Center, I figured I would drop by and ask them about this first. They were very adamant that I NOT use any sort of contact cleaner in the charge port or cable connectors under any circumstances. They were clearly a bit freaked out that I would even suggest it. They said the only thing I should use, and very carefully, is compressed air like those cans you get for blowing out computer keyboards.

I'm sure Tesla wouldn't recommend it, but I do it about every 6 months as preventative maintenance, and also after a road trip where I've used several superchargers, since the SC contacts are dirty from being outside, and they transfer the dirt and oxides into your charge port.

And yes, the black residue that will coat about 8 swabs after cleaning with contact cleaner is not something you can get out of the charge port or charge handles with compressed air.

I don't recommend spraying contact cleaner directly into the charge port or the charge handle. Spray the swab or a small brush, and then use that to clean the port and handle. That way you don't get overspray, and you won't get too much in there.

And obviously, circuit breaker off before cleaning your charge handle on HPWC, or UMC unplugged before cleaning UMC handle.

 

[brucet999]

I'm measuring AC system voltage in two places. One is inside my circuit breaker panel, using the TED system. The other is at the car, using Visible Tesla. The voltage difference between these two will give the drop in voltage across the breaker, wiring to HPWC, HPWC contacts, HPWC charging cord, HPWC handle, and charge port.

In the before cleaning case, and before commencing charge, the voltage both at the panel and in the car was 243 volts (i.e. equal voltage everywhere, as would be expected with no current flow to the car). After commencing charge at 80A, then we had voltage in panel at 241V, voltage at car is 238V, or a 3V drop. 3V * 80A = 240W.

After cleaning the charge port and contacts, before commencing charge, the voltage both at the panel and in the car was 241 volts (again, equal voltage everywhere, as would be expected with no current flow to the car). After commending charge at 80A, then I had voltage in the panel at 238V, and voltage at the car of 237V, or now only a 1V drop. 1V * 80A = 80W.

Odd that cleaning the charge port and HPWC plug contacts should reduce voltage at the panel by 3 V.

 

[SomeJoe7777]

Odd that cleaning the charge port and HPWC plug contacts should reduce voltage at the panel by 3 V.

The after-clean charge was at a different time of day, and I had different loads running in the house. A/C and dryer may have been on, and grid voltage may have changed due to the different time of day as well.

 

[scottm]

Spot the hole that has been cleaned, versus not cleaned!

And here's the juice I use for the job, and showing a shaved down Q tip (on the right) needed to reach in there, compared to an untouched Q tip (on the left).

I will also clean the three tiny holes on the plug (they are the data sense pins).. but the big holes are the ones that matter for current carrying.

FYI - this is my original UMC that came with the car... use the UMC daily at work ... car has 100,000 km on it.
I clean all the charge connections maybe once a year. On the car side too.

 

[scaesare]

I'm actually in need of doing this again.

I'll note that for me it appears to be the pilot signal in one of the smaller holes that typically has the most issues with losing good contact. I'll often get a reduced current warning (30A instead of 40) if that gets dirty