On thinking about this, your vehicle may not have the small start/stop battery in the front wing and if so, then above will not apply.
What are the details of your vehicle please?
Start Stop Battery Replacement
Hello.
It does have. It's an XC40 D4 AWD 2019/2020.
I did measure the 12,6V directly at the auxiliary battery, after removing the negative pole cable. (I took the hard path of not removing the tire though due to not having the proper space to do so, but I did loosen the wheel arch cover partially to reach my hande on the terminals.)
It's now parked since 16:00. Let's see how it behaves tomorrow at 7:00 and if the pop up still persists.
Wish you a great week ahead!
It does have. It's an XC40 D4 AWD 2019/2020.
I did measure the 12,6V directly at the auxiliary battery, after removing the negative pole cable. (I took the hard path of not removing the tire though due to not having the proper space to do so, but I did loosen the wheel arch cover partially to reach my hande on the terminals.)
It's now parked since 16:00. Let's see how it behaves tomorrow at 7:00 and if the pop up still persists.
Wish you a great week ahead!
Hello all,
Pop-up is still there. I wonder if there's any fuse or something that could be causing the auxiliary battery to be electrically disconnected from the rest of the system?
Does anyone has the wiring diagram of this part? I could do some continuity tests.
And does anyone know what's inside the black plastic box on the cable close to the auxiliary battery negative terminal?
Edit: just checked fuse 54 in the engine compartment fuse box and it's ok.
Pop-up is still there. I wonder if there's any fuse or something that could be causing the auxiliary battery to be electrically disconnected from the rest of the system?
Does anyone has the wiring diagram of this part? I could do some continuity tests.
And does anyone know what's inside the black plastic box on the cable close to the auxiliary battery negative terminal?
Edit: just checked fuse 54 in the engine compartment fuse box and it's ok.
Hi again.
Today I spent some more time trying to understand the issue.
I opened the fuse box on top of the main battery and checked all fuses, they are all good.
Then I accessed the auxiliary battery, checked the fuse in the small black box after disconnecting the negative terminal: also good.
Then I disconnected the negative connector on the main battery to reset the system. Waited until the actual voltage dropped below 0,02V.
Removed the aux battery and used a battery tester: tester accused a bad battery.
Connected the battery to a charger, charger took some minutes and said battery was fully charged.
Then used the tester again: still accusing bad battery.
Due to not having another battery available, I've put it back, connected everything, and surprise: the pop-up is gone.
I'll drive a couple of days and see what happens, I assume it will come back again. But now I know the battery is most likely the cause.
Today I spent some more time trying to understand the issue.
I opened the fuse box on top of the main battery and checked all fuses, they are all good.
Then I accessed the auxiliary battery, checked the fuse in the small black box after disconnecting the negative terminal: also good.
Then I disconnected the negative connector on the main battery to reset the system. Waited until the actual voltage dropped below 0,02V.
Removed the aux battery and used a battery tester: tester accused a bad battery.
Connected the battery to a charger, charger took some minutes and said battery was fully charged.
Then used the tester again: still accusing bad battery.
Due to not having another battery available, I've put it back, connected everything, and surprise: the pop-up is gone.
I'll drive a couple of days and see what happens, I assume it will come back again. But now I know the battery is most likely the cause.
Sorry - late to this post. I have an MY19 XC40 T5 and had the same between my second and third service. They reluctantly replaced the battery under warranty. I recently took it in for its 5yr service, noting the Stop/Start had not worked in almost a year. No alarms on the dash though. They advised the support battery was shot again. They said the expected life was around three years, of which it had only been 2.5 years since replacing and not having worked for the previous year anyway. They refused to cover it under warranty again, and tried to charge me A$450 (~230GBP) to replace it, which I politely declined.
I certainly don't expect to have to replace a support battery every two to three years. Surely there's something more sinister at play?
So:
1. Is this a design flaw in the car, if it's killing the batteries much faster than their expected life?
2. Is there any risk (other than some higher fuel consumption) to leave the battery as-is? (they claim the failing support battery is causing the primary battery to fail??)
3. Does anyone in Australia have a third party battery supplier they would recommend to replace it?
Thanks!
I'd say it is a design flaw, expecting what is essentially a motor bike battery to support a car full of electronics. I don't know any details on how the two batteries are connected and how they prevent the small battery from draining when starting the car.
B4 AWD Inscription , Fusion Red, Blond interior. Drivers Assist, Climate, Tinted rear windows and Towing pack.
Ordered 14 Dec 20, delivered 10 March 21
Ordered 14 Dec 20, delivered 10 March 21
1. Yes. Failed support battery is a known issue for MY18-20, you find on the forum multiple reports related to this problem. Support battery failed in my MY20 and Volvo replaced it under warranty with a new, improved unit free of charge.danvito wrote: ↑Tue Oct 01, 2024 7:11 am 1. Is this a design flaw in the car, if it's killing the batteries much faster than their expected life?
2. Is there any risk (other than some higher fuel consumption) to leave the battery as-is? (they claim the failing support battery is causing the primary battery to fail??)
2. Yes. Several components and functionalities are connected to the support battery (not the main battery), such as start-stop park assist and SIM internet connectivity. These could malfunction if the suport battery is depleted (in my case they all did).
