SL Car/12 volt battery bought 1 1/2 year ago. Driven almost 17,000 miles.
Plugged car in (in garage) on New Year's Eve and Charged car to 80%. Did not drive anywhere on New Year's Day and left car plugged in. (No additional charging occurred that night- was also set for 80%). Normally drive car everyday, but not New Years Day so sat OFF for one day in garage.
Early Wednesday morning (garage about 45 F cool) made the following measurements:
Opened car door to pop hood and measure 12-volt battery voltage (door open lights went on briefly then off). Measured 11.89 V. Left car hood open for future measurements.
Next checked main battery status with CARWINGS, then a minute or two later measured 12 volt battery at 11.93 V.
Next left door open with door lights on and measured 11.73 V. Closed door and measured 11.87 V.
Next turned car auxillary on and radio on (closed door) and measured 11.53 V
Next car on auxiliary and radio off. 11.55 V. (Noticed CARWINGS was downloading something)
Next turned Car auxiliary off, but still humming 11.81 V. After humming stopped, 11.88 V.
Finally turned car ON a minute and measured 14.10 V (with car charging 12 V battery)
Not happy resting voltage was below 12 volts at beginning (11.89 V) - getting ready to go bad? Was CARWINGS draining? Just getting old? Cold weather?