Charger overheating

[mhockett]

There are other threads on this subject, but none of them address the root causes. Somebody did post a solution and the reason it works is because of the root problem.

The standard charger, the one that doesn't have the digital screen, is what comes with the car by default. Porsche recommends installing a 50 amp outlet to charge. 50 amp out on long-term charges means you're getting a 40 amp charge.

The charger comes with a 50 amp male plug and the wires that go to and from the central charging unit are 10 gauge thickness. All you electricians out there already know that 10 gauge wire is only good up to 30 amps. Anything more will cause your cord to get really hot. A really hot cord causes your charger to fail. So there is your real cause.

In order for the default charger to work properly, they should have used 6 or 8 gauge internal wire. As it is, if you are in a hot climate like me, your garage is going to be mid-90s or higher and your charger will fail every time. You can only charge your car 10 to 20% at a time before failures.

Porsche does have something that does work. It's their upgraded digital charger. The digital charger allows you to reduce the amperage going to the car. Simply reduce the amperage to 30 instead of 40 and your heating problems go away.

I'm working with my Porsche dealer now to get them to replace my default charger with the upgraded charger... Hopefully at no cost.

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[Genau]

@daveo4EV has more insight on this topic than anyone I can think of. Posting his nickname is like turning on the bat-signal.

 

[Bill33525]

I have a MY21 Audi etron that comes with a charger that look exactly like the Porsche with the exception the cables in and out of the charger body are noticable thicker. The Audi charger runs much cooler 85F even in my hot FL garage, the Porsche 125F . I spoke with my Porsche service agent and was told to run the charger @ 50%. Who wants to take twice as long to charge? I noticed the body of the Porsche charger runs about 125F as well. Would appreciate hearing from anyone who has had an exchange for a cooler running charger.

 

[daveo4EV]

@mhockett's analysis is correct - Porsche is shipping a supply cable rated for 32 amps for a 40 amp load

Porsche should change the cable and provide an upgrade - but to date they have not done so and so far show no signs of doing so.

the PMC+ can be downrated via the 50% button to 20 amps - which will fix the problem
the PMCC can be adjusted in single AMP digits to lower

neither of these are an actual fix since the PMC+/PMCC is sold/represented as a 40 amp charger - which it is _NOT_ reliable in this configuration because of VW/Audi/Porsche choosing a cable from the parts BIN designed for 32 amp loads…

if you want a reliable 40 amp charger for 9.6 kW charge rate I recommend non Porsche EVSE options…

it's also laughable given that the PMC+/PMCC retail/service-parts cost make them the most expensive EVSE's available on the North American market…there are better higher quality more affordable options and Porsche's offerings in this space are not your best option.

The best analysis of the problem seems to be VW/Audi/Porsche are using NEMA 14-50/6-50 supply cable that were originally designed and shipped for 32 amp Hybrids (Panamera, 918 Spyder, Cayenne) - all of these "EV's" are 32 amp 7.2 kW charging EV's and the supply cable is identical to the 32 amp chargers they shipped in North America with those vehicles…

they need to upgrade the supply cable to 8 or 6 gauge wire…

 

[daveo4EV]

I have a MY21 Audi etron that comes with a charger that look exactly like the Porsche with the exception the cables in and out of the charger body are noticable thicker. The Audi charger runs much cooler 85F even in my hot FL garage, the Porsche 125F . I spoke with my Porsche service agent and was told to run the charger @ 50%. Who wants to take twice as long to charge? I noticed the body of the Porsche charger runs about 125F as well. Would appreciate hearing from anyone who has had an exchange for a cooler running charger.

simple - buy a non-Porsche EV charger and it will work way way way better and won't overheat.

 

[daveo4EV]

I think this thread pretty much covers the topic

https://www.taycanforum.com/forum/threads/nema-14-50-supply-cable-heat-data.1940/

Porsche's official response is that if you don't want their 40 amp charger to overheat don't use it as a 40 amp charger - dial down the amps either via the LCD screen w/PMCC or the 50% button with the PMC+

basically Porsche does not have a mobile 40 amp charger option that is correctly designed - there are better alternatives for less money and fewer problems.

 

[Bill33525]

I have a ChargePoint Flex home charger. But this thread is about a potientially dangerious electrical appliance that is provided with the car.

 

[Vercingetorix]

+

= problem solved, at least on the supply side.

 

[daveo4EV]

https://www.taycanforum.com/forum/threads/nema-14-50-supply-cable-heat-data.1940/page-8#post-27227

Porsche admits their 40 amp charger isn't in fact a 40 amp charger cause it will overheat if you use it in that manner…

my response is above.

 

[daveo4EV]

Porsche does have something that does work. It's their upgraded digital charger. The digital charger allows you to reduce the amperage going to the car. Simply reduce the amperage to 30 instead of 40 and your heating problems go away.

I'd argue this is a "mitigation" not a "fix"…

Porsche markets and sells the PMC+/PMCC as a 40 amp charger - but as you point out and other threads they have chosen to ship their EVSE's with substandard cable and then recommend you no longer use them as 40 amp chargers.

that is not a fix - it's a workaround/mitigation - they should replace the 40 amp supply cables with 8 or 6 gauge supply cable's rather than the 10 gauge cable they designed for the 32 amp 918 Spyder Hybrid nearly a decade ago.

it's just wrong, it's poorly designed, they have acknowledged it's wrong, and to date they've done nothing about it - it is clearly not Porsche at it's best.

at this point in time they should refund the money and the $1120 Porsche EVSE cost will more than cover a high quality 40 amp EVSE replacement.

 

[Leawood CT]

@daveo4EV has more insight on this topic than anyone I can think of. Posting his nickname is like turning on the bat-signal.

You weren't kidding, it really is like turning on the bat-signal....

 

[Jhenson29]

I don’t use my PMC+ much, but I did plug it in last summer and do some testing with the 10ga supply cable. I could not reproduce any overheating issues. So, I think it may be marginal. I.e. I don’t think everyone experiences it equally. I’m not condoning the 10ga. Just saying.

FWIW, my 75A EVSE has 6AWG supply conductors. I complained to the manufacturer and they basically told me the device is listed for use as is. So, that’s how it’s been installed and running for over a year (minus the 3 weeks it was out for repair when it died, although I don’t suspect the wire size was a factor).

 

[evn00b]

Another reason why the charger which came with the car is still in its original shrink wrap packaging while a ChargePoint EVSE charges the Taycan @50A without any issues.

 

[DerekS]

I don’t use my PMC+ much, but I did plug it in last summer and do some testing with the 10ga supply cable. I could not reproduce any overheating issues. So, I think it may be marginal.

I think it must build resistance over time. Mine was fine for a full year of use before it started getting unreliable.

 

[Klepper]

I think it must build resistance over time. Mine was fine for a full year of use before it started getting unreliable.

I am in the same position as DerekS - my PMC+ worked fine for about a year, then it started acting up. Any ideas of why that would be?

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