In Dec 2018 I purchased a BMW 120i Sport auto (65 plate) with 34k miles from an independent dealer

Three times in the first month of ownership I noticed warning signs flash up on the central information screen to show a defective light(s) – each time a physical check of all lighting revealed no defect

The dashboard digital clock has to be continually reset as it regularly loses time – as much as 5 minutes over a single week

On 24.01.19 at 0630 the outside temperature was around minus 3 C. I started the car engine without issue but the instrument cluster was inoperative – no speedo/rev counter/fuel gauge/binnacle lighting. The headlights/tail lights worked ok but the indicators did not. After driving for 5 minutes the instrument cluster burst into life and everything (including the indicators) worked normally for the duration of the journey

My initial thoughts were that the main car battery could be failing – I owned a 2009 BMW 320d prior to this and noted certain facilities (heated rear window/stop-start function/radio when engine off etc.) began to stop working before I replaced the battery. All functions were restored on replacing the battery on my 320d. However, the 320d was 6 years old with 120k on the clock before I began to notice signs of battery failure so I wouldn’t expect this with my current 3 year old/35k car

Any thoughts on where these electrical issues may lie?