Jon,

I think it's charging okay. The lower than usual voltage could be the result of a really good battery or something. If it will keep it charged at a slightly lower voltage that's a good thing, since you eliminate the chance of frying the battery with too much voltage.

As far as the red light goes, there is something unique to these cars regarding the light. In years past there was a period on mercedesshop when this subject was discussed at length. You might try doing some searching in this forum. Maybe search battery light, or charge light or battery indicator or something. I'm sorry I can't remember the details.

Old age is setting in and I've just lost too many brain cells in my 62 years on Earth. This statement would be widely confirmed on this forum.

Hope this helps,
Larry

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2001 SLK 320 six speed manual
2014 Porsche Cayenne six speed manual

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