iKarus C42 Series Pilot Operating Handbook page 61

Pilot Operating Handbook for the C42 Series
Therefore, we recommend before the very starting procedure to preheat
the battery by spinning of the starter (2-3 times for 2-3 sec.) without
switched on magnetos.
Once the engine is rotating with a sufficient rpm, the starting procedure
can be accomplished as usually. (switching on the fuel pump, magnetos
and choke)
For additional safety when using the LiFe starting battery, an automatic
overvoltage protection (OVP) must be installed which prevents a
detrimental high charging voltage. An automatically disconnection of the
charging current is displayed by the charging control lamp. To activate the
charging circuit again activate the reset button beside the charging
control lamp or it will happen automatically when reaching a voltage of
approx. 12 V. Repeated light-up of the control lamp signifies an error of
the controller and a direct approach of the next airfield must be
undertaken.
Since October 2018 (serial number 1809-7555 onwards), the overvoltage
protection module is integrated into the electrical charge controller. The
external OVP module is not required anymore. With this integration, the
reset button is removed, as it is automated by the controller. The batterie
charge will be reactivated, when the charge level is dropping below 14 V.
POH C42 SERIES ISSUE1 (B) REV7 25/04/2020 Page 61 of 73