So, is it possible to leave it plugged in too long? like overnight? thanks

 

we leave the ferds plugged in all night and pretty much when not drivin um, never had a prob. don't even plug in the dodge though

 

No problems with it, except your power billIts best to get a timer and have it set 2 or so hours before you want to leave

 

Won't hurt the truck a bit...did it all last winter. Does kill the pocket book as Jake mentioned. Pulls a crazy amount of power.

 

A block heaterdraws a fair amount of power. I've heard 650 watts from someone, and 800 watts from somebody else; not sure what the real figure is. Running the block heater for more than about three hours is just wasting electricity and money. I have a nice Intermatic digital timer that I bought at Home Depot. I set it to turn on my heater 2.5 hours before engine start, which gets my coolant temp up to around 95 deg (according to my Attitude monitor) when I turn the key.

Here is some math to show everyone how much it costs to run a block heater. I am assuming 800 watts continuous power draw, 24 cents per kilowatt hour, and either3 hours (using timer) or 11 hours (not using timer). You can adjust to your own conditions.

3 hours x 800/1000 kw = 2.4 kilowatt hours x $0.24 = $.58 per day or $17.28 per month

11 hours x 800/1000 kw = 8.8 kilowatt hours x $0.24 = $2.11 per day or $63.36 per month

 

Is that how much a kilowatt is - .24 cents?

Also, how did you figure 3 hours useing 2,4 KW, whereas 11 hours only draws 8.8 KW ?

 

It should show on your power bill how much you pay per kilowatt hour. Mine is about 24 cents.

Don't confuse kilowatts with kilowatt hours. A kilowatt is 1000 watts. A kilowatt hour is 1000 watts over the course of an hour. Running an 800 watt block heater for 75 minutes would be 1 kilowatt hour. (0.8 kw x 1.25 hour = 1 kwh)

800 watts is 0.8 kilowatts (800/1000). 3 hours x 0.8 kw = 2.4 kwh, 11 hours x 0.8 kw = 8.8 kwh

Does that make sense?