Furnace blower?

skipro3 wrote:
I have a 2012 Lance 855S camper. The fan for the heater is 2 stage. That means the fan turns slower if the temperature between the setting on the thermostat and the inside of the camper are within 3 degrees, the fan will be on low speed and draw just under 5amps. Call it 4.6amps on low speed. If the camper interior is cooler than 3 degrees from the thermostat setting, then the fan will turn to high speed and draw 7 amps. Soon as the room gets to within 3 degrees of thermostat setting, the fan kicks down to low speed. Also, once the room is up to temp, the heater burner turns off, but the fan continues to run for about a minute or two to scavenge the residual heat off the exchanger. On nights below freezing, say around 25 degrees for the low, my camper will cycle the heater, set at 63 degrees, at a rate of 15 minutes on and 15 minutes off, approx. That means, from just after sunset, until sunrise, about 14 hours total, the fan on the heater will run as much as 7 hours drawing 4.6amps. That's a total of 65 amp hours. I have 100 amp hours of battery, so that just about does in a my battery over night. I have solar to recharge my batteries during the day. They charge about 2.5 amps per hour for the daylight hours; about 8 hours in the winter, for a total of maybe 20ah of charging. That leaves me with a deficit of 45ah I need to make up. To do that, I run my generator so the AC charger on board the camper can recharge the batteries. This charger is a 45ah charger, it takes about 2 hours or so to top off the batteries. I try to run the genny for an hour in the morning, then an hour in the evening to top them off and ready for the night.

BTW, I used a chart recorder from work to log the run times and amp draw for the load on the batteries during the night to get my figures, and again while charging during the day.