Fixed overheating problem with charger and car

[j_scheetz]

I have fixed my charger so that it will not overheat when charging at 40 amp. I think the issue is that the wire that Porsche used for the pigtail and the cable to the car are 10 awg and rated for 40 amps at 194 degrees. I do not think the charger or car like 190 degrees F.

After charging for 3 hours at 40 amps in 95 degrees , I have measured the temperature at the car receptacle at over 170 degrees on the outside of the wire at the handle and over 200 degrees at the receptacle pins.

I re-wired the pigtail with #8 awg wire and bought a #8 awg extension cable to connect to the car. This dropped the temperature in the car receptacle from 218 degrees to 141 degrees.

My plug from the pigtail into the wall receptacle now runs at 112 degrees after 3 hours since the wire does not get as hot and does not heat the plug or charger as much.

I still have higher temp at the charger where the pigtail connects into the charger since I could not change the wire size in the connector to the charger.

The fix would be for Porsche to change the pigtail wire and the wire to the car with #8 awg wire. The larger wire flows the 40 amps with far less heat.

I had posted this in another thread on charging but was thinking that it would be better in its own thread.

Sponsored

 

[RBGtaycan]

I have fixed my charger so that it will not overheat when charging at 40 amp. I think the issue is that the wire that Porsche used for the pigtail and the cable to the car are 10 awg and rated for 40 amps at 194 degrees. I do not think the charger or car like 190 degrees F.

After charging for 3 hours at 40 amps in 95 degrees , I have measured the temperature at the car receptacle at over 170 degrees on the outside of the wire at the handle and over 200 degrees at the receptacle pins.

I re-wired the pigtail with #8 awg wire and bought a #8 awg extension cable to connect to the car. This dropped the temperature in the car receptacle from 218 degrees to 141 degrees.

My plug from the pigtail into the wall receptacle now runs at 112 degrees after 3 hours since the wire does not get as hot and does not heat the plug or charger as much.

I still have higher temp at the charger where the pigtail connects into the charger since I could not change the wire size in the connector to the charger.

The fix would be for Porsche to change the pigtail wire and the wire to the car with #8 awg wire. The larger wire flows the 40 amps with far less heat.

I had posted this in another thread on charging but was thinking that it would be better in its own thread.

Presumably you are using the (problematic) Porsche charger?..for most folks not comfortable with doing their own re-wiring (god bless you!), the best route is probably dropping the charge rate from 40 amps to 30 amps...that's still fast and won't cause overheating in my experience. Lots of dialog on this issue in this forum btw.

 

[Tooney]

In case you have not seen this earlier thread: [North America] - FAQ: the ultimate guide to the Porsche EVSE PMC+/PMCC/PWCC | TaycanForum -- Porsche Taycan Owners, News, Discussions, Forums

 

[DuffNation]

Presumably you are using the (problematic) Porsche charger?..for most folks not comfortable with doing their own re-wiring (god bless you!), the best route is probably dropping the charge rate from 40 amps to 30 amps...that's still fast and won't cause overheating in my experience. Lots of dialog on this issue in this forum btw.

Great tip… how do you change from 40 amp to 30 amp? Or, is this the same as 50%? (which is where I have mine set to prevent the overheating)

 

[mjw930]

Or just buy and install a better EVSE. But it's a novel fix, good for you.

 

[snstevens]

I have fixed my charger so that it will not overheat when charging at 40 amp. I think the issue is that the wire that Porsche used for the pigtail and the cable to the car are 10 awg and rated for 40 amps at 194 degrees. I do not think the charger or car like 190 degrees F.

After charging for 3 hours at 40 amps in 95 degrees , I have measured the temperature at the car receptacle at over 170 degrees on the outside of the wire at the handle and over 200 degrees at the receptacle pins.

I re-wired the pigtail with #8 awg wire and bought a #8 awg extension cable to connect to the car. This dropped the temperature in the car receptacle from 218 degrees to 141 degrees.

My plug from the pigtail into the wall receptacle now runs at 112 degrees after 3 hours since the wire does not get as hot and does not heat the plug or charger as much.

I still have higher temp at the charger where the pigtail connects into the charger since I could not change the wire size in the connector to the charger.

The fix would be for Porsche to change the pigtail wire and the wire to the car with #8 awg wire. The larger wire flows the 40 amps with far less heat.

I had posted this in another thread on charging but was thinking that it would be better in its own thread.

Congratulations on taking this direct approach to fixing the problem. @daveo4EV will be impressed?

However, I’m curious about whether it is necessary to replace the wire to the car with 8 AWG? I think over 90% of the problem is with the pigtail from the charger to the NEMA 14–50 connector.

Did you try just replacing the pigtail?

 

[RBGtaycan]

Great tip… how do you change from 40 amp to 30 amp? Or, is this the same as 50%? (which is where I have mine set to prevent the overheating)

On the charger screen, go to Settings (gear) | scroll to the 2nd or 3rd window (doing this from memory!) | use the slider for power settings. It holds that setting for the future in my experience - altho it is worth checking!..(I think 50% is 20 amp... at least on mine). Check your plug while charging for excess heat..in my experience 30 amp works fine.

 

[RBGtaycan]

Or just buy and install a better EVSE. But it's a novel fix, good for you.

Agreed. My Porsche unit only used (rarely) on trips. I got an "almost free" JuiceNet charger (installed in my garage) from my electric utility (PSEGLI) and also got a credit for it on Fed taxes - so alternatives can be a no brainer.

 

[daveo4EV]

yes as predicted by EE tables better wire runs cooler - and Porsche could lower their nominal operating temperature with $7.28 worth of higher grade cooper in a 13" power supply pigtail…thanks for confirming our speculation.

I still think it's just easier purchase a well designed EVSE vs. hacking Porsche's - but hey this works also.

 

[j_scheetz]

first... We have grid tied solar so it is far cheeper for us to charge from the solar than from the grid so there are many times that I want to be charging with 40 amps because we have sun. I set this on the charger using the 'slider'. 30 amp charging did not overheat the car or charger, 40 amps would cause an overheat on the charger or the car (charge error, red screen).

In testing with just the fixed pigtail, the car would still error. I bought a 8 awg extension cord for the car cord. The Porsche handle plugs into 1 end and the other end has a handle for the car.

After charging for 200 min at 40 amp. the outside of the Porsche cord right where it goes into the handle was 176 F and inside the socket at the pins was 218 F. The #8 extension cord right where it goes into the handle plugged into the car was 112 F and was 141 F at the pins in the car receptacle. More heat is being generated in the Porsche cable due to the smaller wire (#10). Note that used as a pigtail, that wire can get to 194 F and still be up to code.

 

[Vercingetorix]

I just rigged up a fan with a greenhouse type thermostat. 110 F and the fan turns on and cools the plug/outlet. Cost like $25 total.

 

[DuffNation]

On the charger screen, go to Settings (gear) | scroll to the 2nd or 3rd window (doing this from memory!) | use the slider for power settings. It holds that setting for the future in my experience - altho it is worth checking!..(I think 50% is 20 amp... at least on mine). Check your plug while charging for excess heat..in my experience 30 amp works fine.

Awesome! Thanks!!

Sponsored