# 12V heater for inside of vehicle



## kroppe (May 7, 2000)

Hello

Saw some of these on O'Reilly Auto Parts website. Are these viable for overnight heating of the inside of a vehicle (car/SUV)? Are they safe? Will they drain the vehicle battery to the point of not being able to start the engine after 8 hours of usage?

One unit on O'Reilly's was 150 Watts at 12 volts. Roughly 13 amp draw. So for 8 hours of usage that is a little more than 100 Amp-hours. How much storage does a typical car battery have? This is really a deep cycle application, I realize. 

Looks like a Group 31 deep cycle has 125 amp hours. This seems to rule out a standard automotive starting battery as a power source for 8 hours. Does this make sense? 

Li-Ion battery operated heaters for vehicle interiors? Didn't see any of these. Looking for a solution to car camping in cold weather without running the vehicle engine all night.


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## bobberbill (Apr 5, 2011)

I doubt if it would last very long at all. 13 amps is lot to ask from a battery over a period of time. Car/truck uses a burst of amperage to start. Ever left the dome light on overnight in your car/truck? Dead battery. 1 little bulb and it kills it. I left my laptop chargetr plugged in overnight..Dead battery.


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## kroppe (May 7, 2000)

Thanks bobberbill, makes sense.


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## Liver and Onions (Nov 24, 2000)

kroppe said:


> ........
> Looking for a solution to car camping in cold weather without running the vehicle engine all night.


Small generator ?

L & O


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## bobberbill (Apr 5, 2011)

I was curious, so I went to Amazon and searched 12v heaters. Read the reviews..Almost comical as to what they were. Seems like you'd get more heat from a Bic lighter! Might be better to invest in a -30 sleeping bag..


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## kroppe (May 7, 2000)

L&O that is an option but I don't want to go there. Will probably go with an extra bag. For nights in the 20s I think that should work.


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## john warren (Jan 25, 2005)

are you wanting to heat the vehicle? or just sleep warmer?
they sell, at most truck stops, a "bunk warmer" its an electric blanket,,sort of, 12 volt, you put it on the bunk and it warms up nicely. a blanket over you and your comfy. now will your battery handle it?????? not sure, you will need to read the package and figure out what your battery can do, and what the bunk heater needs.


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## kroppe (May 7, 2000)

Thanks John. I want to sleep warmer. A bunk warmer I found online is 48 watts which is a current draw of 4 amps. For a 9 hour usage that is 36 amp hours. With a battery capacity of 80-100 amp hours, it seems possible the bunk warmer would work. Will give it some thought.


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## JimP (Feb 8, 2002)

Back in the 70's we slept in back of a station wagon heated with a small Coleman portable catalytic heater sitting on a board across the front seats. No electric needed, they ran on white gas but later they were made for LP. Set on low they ran on a small bottle of LP all night. They gave off very little CO but we still left both the front windows cracked open an inch or two to replace consumed oxygen. Later we built the same kind of heater into the side of a camper van. It was vented but we still made sure it had a low oxygen shut off. They still make large ones for RV's but I don't know if small portable models are still around.


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