Serious Design Flaw - No easy access to vehicle if 12v battery is very low

[DHS]

I recently returned from a 2-½ week vacation to find I couldn't get into my Macan 4. The 12-volt battery had discharged during my absence, and so the car couldn't be unlocked. Access to the 12-volt battery is through the hood, but there is no mechanical way to open the hood. The only other way to open the hood is though a cumbersome process which requires an external 12-volt battery (see the manual on "emergency hood release"). In my case, I was advised to have the car towed to my dealer, who opened the hood and was able to jump-start the battery for me. The process took almost an hour for three experienced Porsche mechanics. I hate to imagine having to do this myself far from home. I do own a 12-volt portable jump starter, but having it in the car would do me no good since, with a low battery, the hood is not accessible. This seems to be a serious design flaw. It appears that the battery draws quite a bit of juice when just sitting, and even a new battery (my car was just 3 months old) may not be up the job.

From now on, when I go on vacation for a week or more, I'll connect a trickle charger. You might want to do the same.

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[daveo4EV]

this is common for Porsche's and is pretty similar across all their products…

here is how to recover a Taycan with a dead 12V battery…posted 4+ years ago

https://www.taycanforum.com/forum/search/1689060/?q=cheat&c[title_only]=1&c[users]=daveo4EV&o=date

 

[masmole]

What kind of 12V battery is in the Macan electric? I suppose it can vary by market like how 992 were equipped with either AGM or LiPo batteries depending on market/options at some point.

2.5 weeks is awfully short-lived for an AGM battery, so must be LiPo installed in your car?\

Either way, that sucks. Sorry you had to go through that.

 

[daveo4EV]

https://www.taycanforum.com/forum/t...ut-trickle-charger-or-charging-station.23806/

 

[daveo4EV]

What kind of 12V battery is in the Macan electric? I suppose it can vary by market like how 992 were equipped with either AGM or LiPo batteries depending on market/options at some point.

2.5 weeks is awfully short-lived for an AGM battery, so must be LiPo installed in your car?\

Either way, that sucks. Sorry you had to go through that.

EV batteries have very very small capacities - there is no "starter" motor - so all the 12V battery is therefore is to "wake up" the computer and get the bit 800V battery online - the 800V battery is offline behind a big relay switch so that it's "safe" while the car is idle - so the 12V battery has very very little capacity since it essentially only has to have enough juice to monitor the door unlock mechanisms and wakeup the computer's main computer which controls the 800V battery relay…

one of the reasons OTA updates are "hard" for Porsche VW is they you may need the 12V system to be able to maintain the car's computer for 1-2 hours during a software update - and the 12V battery doesn't have enough capaacity to run the vehicle's systems for very long if the 800V battery is offline for any length of time…

it's truly stunning how "small" the 12V batteries in EV's are - because they really dont' do much of anything or have to feed any high demand systems.

 

[JonoNZ]

Does anyone have a picture of the 12V battery in the Macan?

 

[SergeyIndy]

Serious Design Flaw is the understatement. No reason for it to be this way. This has been a known problem for Taycans with occasional cases still occurring. Therefore, Macan EV community needs to learn to how to prevent it and how to restart it from the Taycan community as others mentioned.

 

[masmole]

iirc, this was in issue with the early Taycan until a software update allowed the HV battery to charge the 12V battery while parked as needed.

Wishful thinking that a software update is all that is needed to prevent 12v discharge on the Macans?

I've left my '23 Taycan gts parked for nearly 3 months while away traveling and all was good when I finally returned home to drive it again.

 

[SergeyIndy]

iirc, this was in issue with the early Taycan until a software update allowed the HV battery to charge the 12V battery while parked as needed.

Wishful thinking that a software update is all that is needed to prevent 12v discharge on the Macans?

I've left my '23 Taycan gts parked for nearly 3 months while away traveling and all was good when I finally returned home to drive it again.

You are correct, software update changed the logic of how many times HV battery recharges the 12V battery, that has solved this issue at scale. However, we still get reports on the Taycan forum of dead 12V battery when car left for a short period of time. Therefore, there is no 100% assurance at this time that you can leave the car for a few weeks without killing 12V. The prevention is to attach a compatible trickle charger that will keep 12V battery charged, however, you need a different device to that has a booster function to revive a closed circuited (dead) 12V battery.

 

[Fly4ever]

I wonder what will happen if the 12V battery be disconnected when the car remains stationary for prolonged time periods.In such a case the hood must also remain open or at least unlatched somehow to allow for easy access to reconnect the battery when we get back and want to use the car again.
I do the same to my wife's new Renault Capture which drains its battery in just 10-15 days.We've left it like this for over 3 months and when reconnected its battery was like brand new.We've been told that the main reason for this drainage is the car's easy access system (keyless entry & lock unlock) because when parked it always scans the area to establish connection with the remote key.This continuous scanning and the alarm as well drains its battery.I was told that there was a possibility for the settings to be erased and everything return to factory settings but it didn't happened,all settings remained as they were.

 

[shawn]

I recently returned from a 2-½ week vacation to find I couldn't get into my Macan 4. The 12-volt battery had discharged during my absence, and so the car couldn't be unlocked. Access to the 12-volt battery is through the hood, but there is no mechanical way to open the hood. The only other way to open the hood is though a cumbersome process which requires an external 12-volt battery (see the manual on "emergency hood release"). In my case, I was advised to have the car towed to my dealer, who opened the hood and was able to jump-start the battery for me. The process took almost an hour for three experienced Porsche mechanics. I hate to imagine having to do this myself far from home. I do own a 12-volt portable jump starter, but having it in the car would do me no good since, with a low battery, the hood is not accessible. This seems to be a serious design flaw. It appears that the battery draws quite a bit of juice when just sitting, and even a new battery (my car was just 3 months old) may not be up the job.

From now on, when I go on vacation for a week or more, I'll connect a trickle charger. You might want to do the same.

Is there a maintenance schedule for the 12 v battery? I did not see this in the owner's manual. Something like...a yearly or periodic check (like they do on ICE car lead acid batteries at regular intervals)? Or perhaps there an internal indicator or warning to have the battery serviced?

Also, if maintenance involves a trickle charger are we talking about just hooking up your level 2 charger to a 110vollt outlet or are we talking about opening the frunk and hooking up a 12-volt charger? My question is focused on maintenance during extreme cold or long down times not reviving a dead battery (as I see that in the manual).

thanks

 

[prime]

Rivian has a similar process. I don’t know why more automakers don’t go to lithium ion batteries. Seems to be a more reliable choice

 

[fubar.droid]

This is a problem we have to deal with despite the issue being present on the Taycan? JFC.. I assumed Porsche would have figured out something.. why doesn't the HV battery just charge the 12V? Unless the HV is dangerously low, there's absolutely no reason that this has to be an issue.


BTW was the car plugged in? The manual recommends keeping it plugged in if going away for a long period of time.

 

[SergeyIndy]

Rivian has a similar process. I don’t know why more automakers don’t go to lithium ion batteries. Seems to be a more reliable choice

Macan EV uses lithium-ion. That is not the issue we are talking about.
The issue is that HV battery does not charge 12v battery properly allowing it to lose charge and lock up. The manual seems to indicate that 6 weeks is the time needed for 12v to discharge:

 

[shawn]

Macan EV uses lithium-ion. That is not the issue we are talking about.
The issue is that HV battery does not charge 12v battery properly allowing it to lose charge and lock up.

Is there an internal indicator that tells you the 12-volt battery needs service? Seems like they have tons of other warnings...that one sounds like a useful one? . Not withstanding that, is there a service schedule for the battery? I did not see one in the manual. Maybe Lithium-ion batteries do not need to be checked like lead acid batteries but surely there is a life cycle health check of some sort so you know when you might need to replace it?

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