The battery was a sensitive part of the vehicule. Then it had to be protected during winter as the cold temperatures had a really bad effect on it.
Following the 21/09/1942 Operating instruction N°D 662/206 related to winter equipment for Kubelwagen the battery was protected in a wooden box connected to the vehicule heater circuit by a piece of tube.
When the car was not running, a petrol wick heater was used in the batterybox to heat the battery.
Note the lettering for winter on the box lid.
