Don Breaks His Taycan - The Saga of the 12v Battery

[KerbMonster]

Ok - be good to confirm what charger connector is being used. With Type2 in Europe the protocol has some nifty data over power line comms where as this seems really straightforward using voltage drops to signal required ac current.
Not sure if this simple protocol would allow the charger to show charge state as it wouldn’t be fine grained enough.
Be hard to see though given such a simple protocol how one charger would fail the 12v and others wouldn’t.

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[louv]

Next chapter of the Saga:

Today I did some electrical work. (Yes, I’ve done this before, my dad was an electrician and I spent a summer as an electrician a very long time ago)

- Replaced outdoor outlet. From a 6-50 to a 14-50. (Before you ask, yes there was a neutral pulled already). Now, by standardizing on the 14-50, I can use either of my charging stations without adapter cords.
- Replaced the ChargePoint Flex’s source cord with a 14-50 plug.
- Replaced the J1772 car cord with a new revision of the cord sent to me by ChargePoint when I described the problem I was having.
- Mounted the Porsche EVSE brackets to my outside post so I can now keep it off the ground when using it.
- Attached a kitten picture. Because my foster kittens are cuter than yours.

Charge Testing shall now resume.

 

[Chuck J]

Great job!
Good luck
You are correct about the kitten

Chuck J

 

[SFEVER]

Next chapter of the Saga:

Today I did some electrical work. (Yes, I’ve done this before, my dad was an electrician and I spent a summer as an electrician a very long time ago)

- Replaced outdoor outlet. From a 6-50 to a 14-50. (Before you ask, yes there was a neutral pulled already). Now, by standardizing on the 14-50, I can use either of my charging stations without adapter cords.
- Replaced the ChargePoint Flex’s source cord with a 14-50 plug.
- Replaced the J1772 car cord with a new revision of the cord sent to me by ChargePoint when I described the problem I was having.
- Mounted the Porsche EVSE brackets to my outside post so I can now keep it off the ground when using it.
- Attached a kitten picture. Because my foster kittens are cuter than yours.

Charge Testing shall now resume.

Good Job! I really hope this new wiring & cable helps mitigate the issue for you

 

[r553]

Good work. We stand by for more results.

 

[tomjmoen]

That looks like it works exactly like every other Porsche. Cannot understand the 12 volt. Why not a 12v capacitor? What does it do?

My Prius has a 11 year old 12 volt battery. It has never been jumped, never been replaced. My 911 battery died only a couple years in but Porsche St Paul replaced it for free. That one lasted <3 years and was told it would be $535 parts for the battery and $125 for battery at Bellevue Porsche. That was in 2015. I went with Napa AGM battery, with a 96 month warranty for $168 (list was $225 but their bucket sale took 25% off) best of all, the Napa guy pulled the old, installed the new, for free. After 6 years going strong.

 

[SFEVER]

Next chapter of the Saga:

Today I did some electrical work. (Yes, I’ve done this before, my dad was an electrician and I spent a summer as an electrician a very long time ago)

- Replaced outdoor outlet. From a 6-50 to a 14-50. (Before you ask, yes there was a neutral pulled already). Now, by standardizing on the 14-50, I can use either of my charging stations without adapter cords.
- Replaced the ChargePoint Flex’s source cord with a 14-50 plug.
- Replaced the J1772 car cord with a new revision of the cord sent to me by ChargePoint when I described the problem I was having.
- Mounted the Porsche EVSE brackets to my outside post so I can now keep it off the ground when using it.
- Attached a kitten picture. Because my foster kittens are cuter than yours.

Charge Testing shall now resume.

If I’m not mistaken the Charge point unit is not rated of external use. Rather side of home / garage

 

[louv]

If I’m not mistaken the Charge point unit is not rated of external use. Rather side of home / garage

It is rated for outdoor use.
I asked about snow. They said, “no problem.”

 

[ron_b]

That looks like it works exactly like every other Porsche. Cannot understand the 12 volt. Why not a 12v capacitor? What does it do?

The 12v supply is for things like the console, computers, radio, lights, all things you don't want to run 800v too.
Yes I could imagine a super capacitor dampening the DC-DC converter but the idea is that the DC-DC converter does not (generally) run when vehicle is powered off and not charging. However, there is still needs on the 12v supply like the computer and surveillance with GPS and cellular data fielding requests for things like pre-conditioning. All EV makers I know just use a 12v battery to handle these off-line needs and supply a very good buffer while driving as well.

 

[KerbMonster]

When the car is ‘off’ the 800v battery is isolated. The 12v system is used to power the ECU’s which trigger the various relays to connect the high voltage battery.
Couldn’t use a capacitor as they don’t hold their charge for very long compared to a conventional battery.

 

[louv]

Great news! Nothing changed! Oh wait...

Sigh. Even with the new ChargePoint J1772 cable, the car still got in a state that wiped out the 12v battery.

Fail.

 

[tomjmoen]

When the car is ‘off’ the 800v battery is isolated. The 12v system is used to power the ECU’s which trigger the various relays to connect the high voltage battery.
Couldn’t use a capacitor as they don’t hold their charge for very long compared to a conventional battery.

Long hold capacitors will hold a charge forever. Why Tesla is looking to move from batteries to lighter, smaller, much higher capacity, faster charging capacitors. If you ever worked on an old CRT TV set, you know capacitors can keep a charge forever.

 

[KerbMonster]

All capacitors leak. Some more than others but it is not indefinite
Ironically, yes have worked on old crt tv’s. Yes a long time but not forever.
Energy density is laughable compared to lithium ion battery tech.
What is likely however is a hybrid - batteries are better storage but don’t like cycles or heavy loads (either charging or discharging). Decent capacitors would allow a buffer giving huge performance potential with less stress on the battery pack.
Anyway, right now today I don’t see a practical cost effective option to a simple 12v battery.

 

[Miwa]

If the software bug is draining a chemical battery, it'll also drain a capacitor. The energy storage medium isn't the issue.

 

[ron_b]

Long hold capacitors will hold a charge forever. Why Tesla is looking to move from batteries to lighter, smaller, much higher capacity, faster charging capacitors. If you ever worked on an old CRT TV set, you know capacitors can keep a charge forever.

I am familiar with how long a capacitor can hold a charge (if not bled) but the issue is that it take the circuitry does take potentially several amps at times.

C = Q / V
W = C * V^2 / 2

Note W is Wattage in Watt-Seconds
So even a modest sized 200 Farad 12V Super Cap would provide 14400 WattSeconds or 14.4kW for 1 second.
Or 4 Watt Hours of energy. So the car would need to constantly recharge the capacitor.
Super Capacitors are of use when running the clock in your PC which take uA. And can start a car when large enough,
but if there is continuous drain they will not survive. Sure there are >>200F capacitors but then they start getting large.
The power density is not so clear. My son make a Coil Gun as a home school project years ago and we got to play more with this technology.
Though I am a SW Engineer, my father was an Electrical Engineer and I learned thru osmosis.
Also for tube TVs, I helped my dad build a B&W and then Color Heath Kit TV when I was a kid. I recall him getting hit with 35kV off the flyback transformer capacitor. His arm was sore for weeks. It left an indelible memory for me.

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