[Gordyboy]

i have had issues with a flat battery when returning from a 3 week trip away . I posted before about this but very little response. I am due to go away again soon and I would like to know what trickle charger is best for my M5 C? Most people say Ctek. Anyone had same issue?

[Maxlude]

I keep mine topped up with a Noco genius 3500 (3.5amp) it's been a great charger I've had for years. Waterproof, does lithium-ion 12v. It takes 2-3days to fully charge the F90 main lithium-ion batt. I just leave it connected to my other car and then hook it up to my F90 if I haven't used it for a month. Can just leave it outside in the rain or snow. This model has been replaced by the Noco genius 5amp now.

[RockEnterprises]

I've just bought a CTEK - works a treat. I don't plan in using my car over he Winter.

[aks]

Over the past 3 years, with lockdowns and WFH most of the time, my 2019 M5 didn't move for many weeks at a time - I was worried about a flat battery. However, I am pleased to report I never experienced any issues, the car always started as normal.

Now, the display key is regularly flat as a pancake.

** edit ** just noticed the date of these posts (so close to the top and confused me ☺), oops!