speaking of block heater..can it be run off of an inverter

[chinaman]

I just saw a thread regarding a block heater so it got me thinking
I am heading north, almost canada for most of the winter with my camper and I don't want to start the generator for 3 hours every time I want to start my truck, these things seems to start relatively well in cold weather but I am not sure if it will be too cold.
can I get an extra battery and a 1000 watt power inverter set on a timer to run the block heater and then connect the battery to a charge circuit similar to the trailer wiring so when the truck is running it will be charged and ready for the next morning?
Thanks

[atvrider93]

it should in theory work if the inverter can handle the amps that the heater requires which is I believe 30A. the other question is if the battery will hold enough charge to heat it for 2-3hrs. I have no idea what the case is there but if I had to guess I would say thats probly not gonna work. unless you get a really good deep cycle battery you'll kill it real quick, also

[chinaman]

I don't know about 30 amps, although it could be the case
I read somewhere that it uses a touch less than 1000 watts which equates to about 9 amps of 110ac power (W=VA)????

Maybe someone that knows this kinda stuff like the back of their hand will chime in

[raptorsrock19]

Give me the specs of the heater and I will tell you how to wire it up.

[GAS]

9 Amps sounds about right, but how many amps is a 1000 to 1500 watt inverter gonna take to run?
From what I've read up on (ya got me thinking) its gonna take 200 amp/hours just to run an inverter at that out put for just one hour.
The batteries sized to start our trucks, While rated at 900+ CCA only put out about 70 amp hours continuous. So some quick math tells me its gonna take about 9 batteries to warm your truck for three hours, and the alternator from the Queen Marry to charge them back up.
This is the site i got some of my info from.

http://www.donrowe.com/inverters/inverter_faq.html#how_long

Now maybe you can cut out the inverter and run the heater on DC power, but im thinking you are gonna have a bed full of batteries either way

Good luck!!

[caissiel]

Heat your truck with the power plant for 15 to 20 minutes, might be just enought to get going at -20 F. When I plug in, in winter I never plug for more then one hour. The unit will kick off after a period of time. You don't need the water to boil. Just imagine heating water in a 600Watt kettle.

As for the use of a inverter the plug uses 600watt and will kick off on temperature and will not draw power for a full 4 hrs.

[chinaman]

Well this is looking a little less feasible than I was thinking. Thanks for the great input. How do your trucks start at or below 0 degrees?

[Barry Smith]

I think I read these are 1500 watt heaters. If thats true they are pulling 12.5A.

[caissiel]

In the deep north DC heaters to help with start.
And heating the oil is much more efficient. Takes less power with a pan plug 12V Heater core.

[aquamans350]

From what I've read, the block heater is rated at 1000W

Typical inverters run 85% efficient, so to run 1000W heater load, it's drawing nearly 1200W from the battery. Inverters will shut off when battery voltage drops to about 10.6V which is the state just above what's considered dead. 1200W @ 10.6V = 113amps from the battery.

Standard lead acid batteries are designed for high current, intermittent use only like starting. If deeply discharged like running block heaters, they'll tend to sulfate and prematurely die irreversibly

Running a block heater is better served by using deep cycle batteries. The Optima yellow top batteries that fit our trucks are rated for ~50AH each. I'm reading one should not discharge down below 20% of capacity. I've also read starting takes 2-5% of battery charge, so my guess is a pair of these batteries will run a heater for about 40-45minutes max and maybe have enough juice left to run the glow plugs and starter to turn the engine.

Then the issue is running the engine long enough to charge them back up.

I'm wondering if it's feasible to simply run 12V via relay into the block heater instead. It's just a simple resistive element, so instead of getting 120VAC, it runs off 12VDC. It'll draw approx 1/10 the current and take longer to heat up of course.