22KW OBC FAILURE INSIGHT & POSSIBLE SOLUTION

[prj]

@prj how do you check the OBC warranty ? Are you able to check it on your own or you ask the dealer ?

@ct14garage can help you if he has time.

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[prj]

I remembered wrong, it's not 8 years, it's 5 years.

Here the relevant info on my car:

 

[whitex]

My turn again, 4 months after replacing the 19.2KW OBC, just died again. It seems Porsche design reliability is trending down - the first one lasted 21 months.

EDIT: Correction. After some further investigation, it seems the OBC is still functional. Apparently there is some issue with one of my EVSEs. Got the car to charge on another 80A/19.2KW EVSE. Will look into more details in a week or two (no time sooner, will just plug in a temporary spare for the meantime).

 

[freeforall]

My turn again, 4 months after replacing the 19.2KW OBC, just died again. It seems Porsche design reliability is trending down - the first one lasted 21 months.

This is crazy and to be honest stressful since you can’t know when and where this will happen. Can’t you guys in the US report this to NHTSA? It might put some pressure on Porsche to get this fixed for once and all. Unfortunately we don’t have such a thing in EU to my knowledge.
Mine broke once after 2 years. Seeing that it happened to you 4 times, it feels like that I will have it again soon

 

[whitex]

This is crazy and to be honest stressful since you can’t know when and where this will happen. Can’t you guys in the US report this to NHTSA? It might put some pressure on Porsche to get this fixed for once and all. Unfortunately we don’t have such a thing in EU to my knowledge.
Mine broke once after 2 years. Seeing that it happened to you 4 times, it feels like that I will have it again soon

NHTSA only cares about safety issues. Not being able to charge is not considered a safety issue. This is only my 2nd time, but there are others on this forum who have replaced theirs more than 4 times. I'm just concerned that one installed in 2022 lived 21months, while one installed in 2025 lived 4 months - the quality trend is not encouraging. Sadly, you really don't know when it will strike. It died about 15% SoC into a charging session on both occasions, so not even after a prolonged charging time. Both times it was after a longer drive, but come on, are Porsches really designed to be garage decorations, where 150 mile drive pushes them beyond the design envelope? I wasn't tracking the car, just regular highway driving, some of it in heavy traffic. I think it's just extremely poor reliability designed by Porsche (and yes, I realize they outsource to suppliers, but in the end, is it their design, and they they set acceptance criteria - every Porsche car is built primarily from parts made by suppliers).

 

[freeforall]

NHTSA only cares about safety issues. Not being able to charge is not considered a safety issue. This is only my 2nd time, but there are others on this forum who have replaced theirs more than 4 times. I'm just concerned that one installed in 2022 lived 21months, while one installed in 2025 lived 4 months - the quality trend is not encouraging. Sadly, you really don't know when it will strike. It died about 15% SoC into a charging session on both occasions, so not even after a prolonged charging time. Both times it was after a longer drive, but come on, are Porsches really designed to be garage decorations, where 150 mile drive pushed them beyond the design envelope? I wasn't tracking the car, just regular highway driving, some of it in heavy traffic. I think it's just extremely poor reliability designed by Porsche (and yes, I realize they outsource to suppliers, but in the end, is it their design, and they they set acceptance criteria - every Porsche car is built primarily from parts made by suppliers).

When mine died it wasn’t after a long drive. It was charging a few % in my garage after I used it for 10 km in the morning.
Also when it happened to me it wasn’t just that it couldn’t charge anymore. The car just stopped moving and then the 12v battery died after 48h. It was a nightmare even to open the door as we didn’t succeed to use the manual key. The guy who came to tow it had to use a cable to grab the door handle through the window annd open the door.
Noted for NHTSA. I thought they would care about electrical failure causing the car to stop. Like when there was the 12v battery issue but probably it had some security implications.

 

[whitex]

Quick update. It seems I spoke too soon. While my symptoms were identical to when OBC died, I did some further investigation and it looks like my OBC is still functional, just not with its usual EVSE (the one which it has been charging from for over 2 years now, previously serving other EVs). Not sure what is causing the issue, as the EVSE is not throwing any errors, but the Taycan will not charge from it. Tried another EV (Audi) on that same EVSE, it appears to engage the relay but only for a short time, then shuts it off - end result it's not charging. Not a lot of time over next couple of weeks to debug in depth, will use a portable EVSE for now.

 

[HarryPAG]

Hello all, i have the same issue- overal question about the mosfets- do they have too low a power rating?

 

[prj]

Hello all, i have the same issue- overal question about the mosfets- do they have too low a power rating?

Yes.

 

[HarryPAG]

thank you, so that means when i change it to nexperia - the problem is solved? No any other issues?

 

[whitex]

PS: It’s not so much that they don’t care about it, but all the Electrical system of the Taycan wasn’t designed nor built by them. They relied on LG, MetaSystems, HITACHI and plenty others. Those are the ones really responsible so Porsche doesnt bother with it. It’s not their job to fix their mess.

When the OBC fails and Porsche repairs it for you for free, Porsche then claims this cost back from Metasystems. Every single time.

If it's free to Porsche, and their dealers make money on it, why would Porsche discontinue the 22kW OBC? It's just cutting off free money to their dealer network which does the swaps.

 

[snoopy]

If it's free to Porsche, and their dealers make money on it, why would Porsche discontinue the 22kW OBC? It's just cutting off free money to their dealer network which does the swaps.

Because MetaSystems would go bankrupt if it needed to provide 22kW charger for free don't you think?

 

[whitex]

Because MetaSystems would go bankrupt if it needed to provide 22kW charger for free don't you think?

How is that Porsche's problem? It should force MetaSystems to redesign so it's reliable if they don't want to go bankrupt, no? They've had 7 years already.

Do you think Porsche does this with every part supplier, all it takes is make a shitty part so Porsche will just absolve the supplier from their warranty obligations by saying something along the lines of "oh, don't worry about providing free replacement parts, we'll just tell customers the part is not available anymore, because we don't want you to go under"?

 

[snoopy]

How is that Porsche's problem? It should force MetaSystems to redesign so it's reliable if they don't want to go bankrupt, no? They've had 7 years already.

Do you think Porsche does this with every part supplier, all it takes is make a shitty part so Porsche will just absolve the supplier from their warranty obligations by saying something along the lines of "oh, don't worry about providing free replacement parts, we'll just tell customers the part is not available anymore, because we don't want you to go under"?

It's easy from the outside to see only one side of the story. There are contracts behind it, which god knows what is written inside. Do you think Porsche would not like us to have a 22 kW OBC replacement that would work? If it were that easy, new models would already have the 22kw OBC, but there is not even an option anymore. Not even that, but the EV market that has 22kW OBC's is slowly disappearing. Everybody seems happy with 11kW.

 

[F1Ruaraidh]

How is that Porsche's problem? It should force MetaSystems to redesign so it's reliable if they don't want to go bankrupt, no? They've had 7 years already.

Do you think Porsche does this with every part supplier, all it takes is make a shitty part so Porsche will just absolve the supplier from their warranty obligations by saying something along the lines of "oh, don't worry about providing free replacement parts, we'll just tell customers the part is not available anymore, because we don't want you to go under"?

It''s never that simple.

Porsche will have specified the requirements. That will have included sign off and acceptance specs. This is a Tier 1 part.

Porsche is ultimately responsible for
1) not defining the test cases correctly
2) not thinking about single phase use on a three phase charger
3) not specifying the overload spec (defines the silicon rating)
4) not properly defining durability and thermal testing (to properly define how the silicon derates at temperature)

All of the issues are knowable, should have been found in any self-respecting DVP&R plan and fixed long before production.

Porsche made a great car but their hubris made a terrible EV.

J1.1 should have been the D sample validation prototype and J1.2 the launch vehicle.

Don't even get me started on the stupidity of the 150kW DCDC converter (derated to 105 in my case due to yellow ring of death at 60% SoC....)

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