Would be good if people can post the year, of their model when posting MHEV goes bad. Wondering if its post Covid Models or all all P400's potentially. I have a 2020 (About to roll over 40k) and good so far, as of the drive this AM.

 

2026 Octa with 2,000 miles - check engine light came on last week (solid light not blinking). Car was on highway and driveability not affected. Took it to dealer and found faulty MHEV & Control Pack and replaced both. As an aside I also have a 2021 P400 with 58k miles and no issue with MHEV system…..so far.

 

Does anyone know where to find the details? / specs for this battery : LR181079 / 429123487 battery spec sheet (Ah/Wh, dimensions, weight, chemistry, etc.) - they are not in Topix or anywhere else I looked at. I wonder if this can be replaced with a non OEM ? - Thanks.

 

The issue seems to be localized with the DC to DC converters. From what I'm understanding this is primarily due to low voltage in the primary 12 volt battery. Especially during initial startup, the low voltage will cause an amp spike in the DC to DC converter contactors and basically weld them shut. To try and avoid this from being an issue, we are starting to recommend preemptive 12v battery replacement, and a method of trickle charging like a quality solar trickle setup. Being that most of these manufacturers are using mild hybrid technology, these are going to be some of the additional components in these systems that can cause reliability issues.

 

Do you have any recommendations on when to change the battery? (years / miles)

 

This is wild how many people I’m finding with these issues at the same time. This DC to DC nonsense left me and my family stranded today. 48k miles ‘23 defender

 

I'm believing what Sarek mentioned about the DC to DC converters having an effect on the 12v battery. I happened to be watching several videos from Simon from Powerfuluk this month about the DC to DC converter. Though not confirmed but several comments mentioned that in the last month a lot more people are having issues with the DC to DC converter. Some in the comments believe including Simon that the latest update for the mild hybrid JLR did a fix that could be harming the DC to DC converter. Again not confirmed but it is a coincidence there has been a spike of issues in the last month.

 

Please be specific; by "latest" do you mean 4.3.0, or 4.4.0?

 

That’s interesting. I don’t know the version I had. But it was whatever version was before the latest in the northeast USA. I was purposely ignoring the latest version, as it was talking about more ai capabilities. Being in the tech industry, all I hear there…. is more software that will require better hardware than what I had in 2023. Inevitably will slow down something. Wasn’t interested. But software also seems to be a possibility because everyone seems to be having trouble around the same time. Grrrr

 

Based on the video 4.4.0. Simon responded to a comment that it even could be where you live in a colder climate.