Not really. As soon as outdoor temperature drops below +5C, the "Smart charging" regime fades away and the battery will get "full blast" charging - at approx. 14.8 Volts full time when engine is running. I'd say the battery will be fully charged.
E.g. yesterday it was -3C. Two 30+ min drives charging at the max voltage - as on day before, and on the day before that...
The voltage drops before driving are due to running Webasto 10-15 mins.
When it gets really cold (-20C and below) as battery's charge acceptance deteriorates certainly need to keep eye on "energy balance" of the battery. To be on safe side, the rule of thumb we use is: in average need to run vehicle as long as Webasto is used for preheating.
E.g. yesterday it was -3C. Two 30+ min drives charging at the max voltage - as on day before, and on the day before that...
The voltage drops before driving are due to running Webasto 10-15 mins.
When it gets really cold (-20C and below) as battery's charge acceptance deteriorates certainly need to keep eye on "energy balance" of the battery. To be on safe side, the rule of thumb we use is: in average need to run vehicle as long as Webasto is used for preheating.