Its been really cold up here in Ontario the last couple of weeks. I have been watching the voltmeter in the truck closely and noticed there is alot of load starting the truck (glow plugs,starter), lasting until the grid heater shuts off. The system has a hard time maintaining 11 volts (from dash meter) during this time and jumps over 14 volts when the heater shuts off. I use the truck mostly for short trips to work at this time of the year and am concerned about how much power is drained from the batteries on each start-up vs. the charging time. With these loads can I drive 10Km to and from work for a week and still expect to have enough power to start the truck (so far so good). I know I should take it out for some good run's, but I can't do it every day. Any thought's?