another faulty 12V ?

[asosnikhin]

Unexpectedly, my Enyaq 85 died due to a flat battery yesterday. I returned home after a drive of about 35 miles around 5 PM, parked the car, and locked it. There were no error messages or warnings, and the main battery still had 11% charge left. Later in the evening, I noticed that Octopus couldn't start charging the car, and the Skoda app reported a low battery. I decided to check what was happening, but it was too late; the car wasn't responding to the keys. I could only open the passenger door, but that didn't help. The AA arrived quickly, jump-started the car, and confirmed that the battery was empty. The technician couldn't determine the cause, and it's clear that I need to contact the dealer. I'm very concerned about ending up in such a situation far from home with my family. Has anyone encountered a similar issue? It's very strange that the battery completely drains in 3-4 hours with the car locked.

[Gary R]

I carry around a battery booster just in case that happens. Not that it's likely to be something that's going to happen very often, but always nice to be prepared.

A quick search on Amazon will throw up lots of hits at a variety of prices. Doesn't need to be high powered, since it's not having to turn an engine over, just supply enough current to switch the drive battery's contactors.

[riki1]

When you come home with a car that only has 11% of its battery left, you have to charge it immediately, regardless of the price of electricity and don't wait for a cheaper tariff.

[asosnikhin]

When you come home with a car that only has 11% of its battery left, you have to charge it immediately, regardless of the price of electricity and don't wait for a cheaper tariff.

It's not entirely clear how this would help in the situation. As the AA mechanic explained to me, the 12-volt battery does not charge when the car is locked, even if the main battery is being charged at that time. The car is only 4 months old, and this is clearly some kind of malfunction.

[asosnikhin]

I carry around a battery booster just in case that happens. Not that it's likely to be something that's going to happen very often, but always nice to be prepared.

A quick search on Amazon will throw up lots of hits at a variety of prices. Doesn't need to be high powered, since it's not having to turn an engine over, just supply enough current to switch the drive battery's contactors.

Yes, I agree, it seems like a sensible solution for such situations. The main thing is to make sure this booster doesn't run out of charge at the crucial moment either.

[riki1]

When you come home with a car that only has 11% of its battery left, you have to charge it immediately, regardless of the price of electricity and don't wait for a cheaper tariff.

It's not entirely clear how this would help in the situation. As the AA mechanic explained to me, the 12-volt battery does not charge when the car is locked, even if the main battery is being charged at that time. The car is only 4 months old, and this is clearly some kind of malfunction.

If you had done that, both batteries would have charged without any problems, the mechanic was talking nonsense.

[CrowSysE243]

It's not entirely clear how this would help in the situation. As the AA mechanic explained to me, the 12-volt battery does not charge when the car is locked, even if the main battery is being charged at that time. The car is only 4 months old, and this is clearly some kind of malfunction.

That probably used to be the case, however my car (iV80 with SW version 3.5 plus several lower level software module updates) now (for at least 1.5 months) charges the 12V battery from the HV battery when the 12V battery SoC drops to 50% and charges up to 90%, whether the car is locked, unlocked, and independent of whether the car is connected to a charger or not. It is possible, however, that this does not happen if the HV battery SoC is too low, in order to conserve HV battery charge. I have not tested the behaviour below 30% HV SoC. As the 12V battery SoC reduces and before it has reduced to 50% I do see that the some remote control functions are disabled, so Octopus is not able to control charging, however I have never experienced a problem with unlocking the car using the keys and they become available again as soon as the 12V battery charging starts.

It also starts charging the 12V battery as soon as the HV battery starts charging. I have not checked the behaviour in detail but the 12V battery is charged to %.above 90%.

I know that there are differences between the hardware and software for my iV80 and the 85, however I would be surprised if the characteristics of the 85 were much worse than my 80, so I suspect there is a fault. Whenever I have driven the car for >30 miles the 12V SoC percentage has been in the high 90s. Normally I see about 5% reduction in 12V SoC in over 12 hours. This is with an OBD2 scanner plugged in but not connected and the approach lighting disabled to stop the lights coming on as I walk about the house. I have increased the rate of discharge to nearly 10% per hour by leaving CarScanner connected and recording 30 measurements per second. This caused the 12V battery current drain to be over 2 amperes.

The car getting into a state where the 12V battery is sufficiently discharged that the car cannot be opened with the keys within 3 to 4 hours after being driven 35 miles should not be possible.

[asosnikhin]

It's not entirely clear how this would help in the situation. As the AA mechanic explained to me, the 12-volt battery does not charge when the car is locked, even if the main battery is being charged at that time. The car is only 4 months old, and this is clearly some kind of malfunction.

That probably used to be the case, however my car (iV80 with SW version 3.5 plus several lower level software module updates) now (for at least 1.5 months) charges the 12V battery from the HV battery when the 12V battery SoC drops to 50% and charges up to 90%, whether the car is locked, unlocked, and independent of whether the car is connected to a charger or not. It is possible, however, that this does not happen if the HV battery SoC is too low, in order to conserve HV battery charge. I have not tested the behaviour below 30% HV SoC. As the 12V battery SoC reduces and before it has reduced to 50% I do see that the some remote control functions are disabled, so Octopus is not able to control charging, however I have never experienced a problem with unlocking the car using the keys and they become available again as soon as the 12V battery charging starts.
battery limit.png

It also starts charging the 12V battery as soon as the HV battery starts charging. I have not checked the behaviour in detail but the 12V battery is charged to %.above 90%.

I know that there are differences between the hardware and software for my iV80 and the 85, however I would be surprised if the characteristics of the 85 were much worse than my 80, so I suspect there is a fault. Whenever I have driven the car for >30 miles the 12V SoC percentage has been in the high 90s. Normally I see about 5% reduction in 12V SoC in over 12 hours. This is with an OBD2 scanner plugged in but not connected and the approach lighting disabled to stop the lights coming on as I walk about the house. I have increased the rate of discharge to nearly 10% per hour by leaving CarScanner connected and recording 30 measurements per second. This caused the 12V battery current drain to be over 2 amperes.

The car getting into a state where the 12V battery is sufficiently discharged that the car cannot be opened with the keys within 3 to 4 hours after being driven 35 miles should not be possible.

Thank you very much for the comment, very useful information, it's a pity that Skoda does not provide the ability to control the discharge of a 12-volt battery without external equipment. Now my HV battery charge is 46% and I've just received a message in the app again: "Battery protection limit exceeded: To continue using the remote control, drive your car to recharge the battery."

[riki1]

The car getting into a state where the 12V battery is sufficiently discharged that the car cannot be opened with the keys within 3 to 4 hours after being driven 35 miles should not be possible.

But he drove most of those 35 miles with the main battery below 20% charge, so by then his 12V battery was probably no longer charging and therefore discharged.

[robem64]

My Enyaq 85 is also 4 months old and reports 12V battery issues - even when the SOC is healthy (75% plus). I've had this warning on the app 10 mins after driving the car and also I had charged the 12V battery using a battery charger just 30 mins before. I'm convinced there's a problem so it's booked into the dealership at end of Jan. In the meantime I've invested in a battery booster just in case!