Trickle Charger for Taycan 12v battery?

[Tooney]

Thanks, I'm finding more and more alarming information about the charging system for the main battery and why they want you to only charge at a minimum 8a with the Porsche 120v charger in your garage. Evidently if you charge at less than 8a it will damage cells in the main battery reducing range but still posing a significant risk of fire due to the cheap on board charger in the Taycan which is still used in all models including the 2021 I just purchased. I'm losing confidence in Porsche as an elite car company.

You are being misinformed and/or you want to misinform others.

I'm told the 12v lithium ion battery is used to run the electronics on the car. If this battery dies then the car is dead.
Pretty silly that an EV with a 74kW main battery must rely on a single 12v battery for its brain with no backup to the main battery which would only require a DC to DC voltage converter. Instead they make you use a trickle charger if you are going to let it sit for a week or two.

If "they" make you use a trickle charger to let your Taycan sit for a week or two, you are paying attention to the wrong "they".

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[simcity]

Thanks for the input. I'm going back to the Porsche dealer on Monday to try to get some answers. The fire risk on the main battery due to the cheap battery management charger still used in the Taycan is a big concern.

Fire risk, from a smart / trickle charger?! No not that I’m aware of. A proper lithium spec trickle charger won’t do any such thing. I’ve used Porsches stuff (white labelled CTeK), actual CTeK and Optimate over the years on cars and bikes with LFP. No issue at all.

On the Taycan; even if the main contactor is energised and also running the DC-DC converter and pushing the terminal voltage to around 14.2v there is no risk attaching a trickle charger to the 12v battery. It just won’t do anything…other than give you a full suite of green fully charged LEDs

 

[Hirschaj]

@Option7 is coming off as a troll spreading misinformation via partial truths. Even if they are not, it’s what they sound like.

 

[Option7]

You are being misinformed and/or you want to misinform others.


If "they" make you use a trickle charger to let your Taycan sit for a week or two, you are paying attention to the wrong "they".

This is coming from a story based on a declarations from a Porsche whistleblower from Porsche in Germany. I will hopefully get the straight story from my
Porsche dealer tomorrow...

 

[Vercingetorix]

Not again.

 

[Andy0565]

I left my car at home for two months whilst away. It was plugged in to my wall charger and sat there happily at around 55%. By the time I got home the main battery charge had dropped to 54%. I thought that the batteries simply lost charge over time but perhaps they topped up the 12v system.

Anyway, no issues when I came to drive it.

I believe it’s important to leave the main batteries charged at around 50%-60% if you don’t plan to use it.

 

[Option7]

You are being misinformed and/or you want to misinform others.


If "they" make you use a trickle charger to let your Taycan sit for a week or two, you are paying attention to the wrong "they".

Fire risk, from a smart / trickle charger?! No not that I’m aware of. A proper lithium spec trickle charger won’t do any such thing. I’ve used Porsches stuff (white labelled CTeK), actual CTeK and Optimate over the years on cars and bikes with LFP. No issue at all.

On the Taycan; even if the main contactor is energised and also running the DC-DC converter and pushing the terminal voltage to around 14.2v there is no risk attaching a trickle charger to the 12v battery. It just won’t do anything…other than give you a full suite of green fully charged LEDs

I'm finding out more information about the main & 12v batteries.
It appears the 12v battery may no longer need to be trickle charged after a software update but the main battery has unresolved issues which evidently Porsche is hiding from Taycan owners.
I found out the reason they have you change the charge rate from 6A to 8A on their 120v charger. If you charge at a rate lower than 8A you will damage main battery cells over time and reduce the range of the battery. I was told by my Porsche dealer that Porsche can repair individual cells rather than replace an entire battery pack on a Tesla. This was not actually true.
I am finding out that back in 2001 Porsche was charging 600Euro to repair a battery cell when in fact they simply activated dormant excess cells in the pack to give the appearance the battery has been repaired. This means the cell that went bad is still there and continues to be a fire risk.
Porsche is doing some really stupid things in their quest to build a world class EV. I just bought one and now regret it. I didn't think I needed to do my normal research when buying a car and simply trust Porsche implicitly based on my previous ownership of a Porsche. My distrust of Porsche has grown the last few days as I learn how they are responding to these main battery issues which their sister company don't have since they chose a higher quality, more expensive battery charging system.
I see my Porsche dealer tomorrow to get the truth, insure my vehicle is safe or return my car.

 

[Tooney]

I see my Porsche dealer tomorrow to get the truth, insure my vehicle is safe or return my car.

To avoid your Taycan battery dying or catching on fire during your trip to the dealer tomorrow, take precautions:

 

[Vercingetorix]

The only reason Porsche upped the 6 amp charging at 120v was to keep the battery from aging out before it could be fully charged.

 

[daveo4EV]

I'm finding out more information about the main & 12v batteries.
It appears the 12v battery may no longer need to be trickle charged after a software update but the main battery has unresolved issues which evidently Porsche is hiding from Taycan owners.
I found out the reason they have you change the charge rate from 6A to 8A on their 120v charger. If you charge at a rate lower than 8A you will damage main battery cells over time and reduce the range of the battery. I was told by my Porsche dealer that Porsche can repair individual cells rather than replace an entire battery pack on a Tesla. This was not actually true.
I am finding out that back in 2001 Porsche was charging 600Euro to repair a battery cell when in fact they simply activated dormant excess cells in the pack to give the appearance the battery has been repaired. This means the cell that went bad is still there and continues to be a fire risk.
Porsche is doing some really stupid things in their quest to build a world class EV. I just bought one and now regret it. I didn't think I needed to do my normal research when buying a car and simply trust Porsche implicitly based on my previous ownership of a Porsche. My distrust of Porsche has grown the last few days as I learn how they are responding to these main battery issues which their sister company don't have since they chose a higher quality, more expensive battery charging system.
I see my Porsche dealer tomorrow to get the truth, insure my vehicle is safe or return my car.

/ignore troll - dubious information and no critical thinking skills

rehashing of unfounded rumors that have been debunked - failure to listen to reason - i’m done!

 

[Option7]

I left my car at home for two months whilst away. It was plugged in to my wall charger and sat there happily at around 55%. By the time I got home the main battery charge had dropped to 54%. I thought that the batteries simply lost charge over time but perhaps they topped up the 12v system.

Anyway, no issues when I came to drive it.

I believe it’s important to leave the main batteries charged at around 50%-60% if you don’t plan to use it.

Thanks, that's great information. I found a Porsche thread for proper battery customer maintenance to always have the battery charged to at least 50% before letting it sit for weeks. This I can do if it will keep the main battery in the best condition. I just wish the dealer would tell me this instead of having to find Other Taycan owners to fill me in on best practices. Thanks

 

[Option7]

The only reason Porsche upped the 6 amp charging at 120v was to keep the battery from aging out before it could be fully charged.

This is what was reported by a Porsche whistleblower from Germany:

"The Porsche whistleblower explained that the Tacan's 800V high-voltage onboard charger used today does not control the charging process well enough and can overcharge some battery cells, causing them to overheat. For safety reasons, overheated battery cells are disabled and isolated from the battery pack, reducing battery capacity and thus the vehicle's range. The problem occurs when the batteries are charged at a low AC speed of up to 7.5 KW, a common use case for all charging, such as at home or on low-speed chargers, the source said."

I am told this is why Porsche has you change the default 6A setting on their 120V charger to 8A to increase the low speed charging rate.
Evidently this is due to the on board charger Porsche is using as opposed to Audi which uses a higher quality charger in their etron (using the same LG batteries) and has had none of these battery issues close to what Porsche is experiencing.
I'm continuing to get to the bottom of this but I believe eventually Porsche will be forced to upgrade their onboard charging system before they severely damage their reputation.
Going to 800v was smart but not using a high quality, high performance charging module which makes using 800v safe is not very bright for a brand I love.

 

[Option7]

/ignore troll - dubious information and no critical thinking skills

rehashing of unfounded rumors that have been debunked - failure to listen to reason - i’m done!

Please direct me toward the information which debunks the information I have found on the Taycan forum as well as the information found in the recent Taycan recalls as recent as Sept/2023.
I'm just looking for facts. If some of the information is incorrect that I'm being given I'm happy to be corrected since I have a Taycan and I don't want it to catch fire in my garage or with my wife driving in the desert between OC & Vegas.

 

[j.w.s]

I'm finding out more information about the main & 12v batteries.
It appears the 12v battery may no longer need to be trickle charged after a software update but the main battery has unresolved issues which evidently Porsche is hiding from Taycan owners.
I found out the reason they have you change the charge rate from 6A to 8A on their 120v charger. If you charge at a rate lower than 8A you will damage main battery cells over time and reduce the range of the battery. I was told by my Porsche dealer that Porsche can repair individual cells rather than replace an entire battery pack on a Tesla. This was not actually true.
I am finding out that back in 2001 Porsche was charging 600Euro to repair a battery cell when in fact they simply activated dormant excess cells in the pack to give the appearance the battery has been repaired. This means the cell that went bad is still there and continues to be a fire risk.
Porsche is doing some really stupid things in their quest to build a world class EV. I just bought one and now regret it. I didn't think I needed to do my normal research when buying a car and simply trust Porsche implicitly based on my previous ownership of a Porsche. My distrust of Porsche has grown the last few days as I learn how they are responding to these main battery issues which their sister company don't have since they chose a higher quality, more expensive battery charging system.
I see my Porsche dealer tomorrow to get the truth, insure my vehicle is safe or return my car.

For anyone reading the above: This is old FUD, long ago disproven. Ignore.

For the Option7: There are are no "dormant excess" cells to "activate", and there is no way for a technician to "disable" certain cells. That's just not how EV battery packs are built - any of them. Someone long ago posted a bunch of FUD from a supposed "whistleblower" that made no sense back then and still doesn't.

 

[Option7]

For anyone reading the above: This is old FUD, long ago disproven. Ignore.

For the Option7: There are are no "dormant excess" cells to "activate", and there is no way for a technician to "disable" certain cells. That's just not how EV battery packs are built - any of them. Someone long ago posted a bunch of FUD from a supposed "whistleblower" that made no sense back then and still doesn't.

Thanks for the info. Can you point me in the direction of articles which disprove what the supposed "whistleblower" said? I understand how Porsche could have designed their batteries to have excess capacity which can be accessed for adding capacity lost due to age or failure. This is just smart design and makes sense but giving the impression they will actually remove individual cells when they fail which is more labor intensive than just a setting in software. I will find out first hand from my Porsche service center how both methods are employed.
I've worked for high tech equipment companies much more advanced than Porsche or any car manufacturer based in Europe which practices this same nascent capability model in manufacturing.
It lowers your manufacturing costs to include all options in the build of every unit and simply activate options via software and worst case add external hardware options in a plug n play fashion that requires no additional wiring or infrastructure which adds to the time it takes to add any of these options. This strategy should work well for Porsche as long as a cell which fails can be disconnected from the array of cells in a way that they cannot overcharge and be at risk for a runaway overcharge event. I do understand these things since I am an electrical engineer and work with similar technologies in far more advanced industrial equipment costing as much as $300M US where cost is no object. Auto manufacturers are held hostage to the cost of every component on their cars as well as the cost to service them under warranty and still be profitable. Porsche is finding their way with their first EV. I'm confident they will do the right thing since their long, storied, reputation depends on it.

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