I replaced the battery in my Boxster last week as it was rather old and not holding its charge. I checked in the week and did a few tests:-
The battery was at 12.4V, engine cold, not running.
Charging at 15.4V at idle and 2000 rpm, nothing turned on.
Fluctuating between 14.2V & 15.2V at idle with lights (including fogs), aircon, heated seats, hrw, blower fan at full & stereo/sat nav on.
Steady 15.2V at 2000 rpm, with all the above on.
I've just duplicated the tests this morning and the battery was still sitting at 12.4V (engine cold, not running).
12.4V is a bit low. Would you say that 15+ Volts charging is a bit high?
Sprintless for the first time in 35+ years.
2007 Porsche Boxster S
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