The thing is, we aren't sure how far down the HV battery this applies to. It makes sense that there is a point at which the HV battery will protect itself at the expense of the 12v. I note that the Coda that Out Of Spec Reviews are restoring had that set at 30%. The car was found after 12 years still at 30% battery, and was able to be driven off simply by using a 12v booster. Subsequent experience showed that whenever the car was left unused it maintained the 12v until it hit 30%, then stopped. It seems to have kept that 30% SoC for more than a decade in the first instance, which is impressive. (They also discovered that the 12v wasn't actually dead and was capable of holding a charge to some extent, even after all that time. Which was also impressive.)
We do not know what the percentage set for the MG4 is, but some people have suggested 50%. That seems ridiculously high to me, but it might be prudent to charge to say 60% before leaving the car for an extended period of time, just in case.
Although I don't really know how much it takes to keep a healthy 12v topped up. My car didn't lose any charge in the HV battery in more than a fortnight. (Actually that's twice now, I'd forgotten the two weeks parked outside my friend's house when we went on holiday in June of this year.) I suspect if the 12v is in good condition it will hold its charge pretty well for quite a while. I left my Golf for 10 weeks at Avonmouth while I went on a cruise, January to March. I had left a battery booster pack in the car just in case, but I didn't need it. The battery, which was relatively new, managed to turn over the 2-litre engine after a bit of huffing and puffing, even after that time. (My friend's Polo was dead when we got to it though, so we needed the booster pack after all.)
excellent work! Now what's your take on what it does? Whist you are at it, "enable ME mode " what is that? I may have inadvertently pressed it ????? or not , so exciting finding a new screen , fingers everywhere.?
