Need Help Battery and Engine in Winter

[Coyote machine]

If you decide to use a canon heater, using propane fuel source you must make sure there is no gas vapor from the ATV; and batteries off gas too, any of which can be an explosive mix of deadly proportions.
A battery tender is different than a trickle charger and is the preferred method of maintaining any battery's correct state of charge. Here is but one example of the tender: Deltran Battery Tender Junior 12V Battery on sale for $20.50

You said you had two batteries go on you in the past winter? What did you do to keep them charged? How often do you you use the ATV during winter months? Are the connections to the battery and the ground wire to the chassis of the ATV clean and not loose or showing any signs of corrosion? You can and should buy a battery terminal sealer at any NAPA or other auto store and spray it on the terminals to prevent corrosion.

 

[MHarryE]

I'm from Northern MN and have no problem starting my Polaris Sportsman 500 in any temp when I need to use it, but then again I don't need to use it when it is lower than -10. I've never had a charger of any kind on the battery. The battery gets used pretty heavy when I plow with the ATV because of the electric lift. My tractor sits in a heated garage and although it has a block heater, my 2 cars and one pickup would sit outside before my tractor does. After all, none of the others are any good if we get a 2 foot snowfall and the ATV plow would suck in that. My ATV sits in my uninsulated machine shed.

 

[pat32rf]

At +20F, nothing gets plugged in around here, but at -20F, everything does. (Its all outside).
The tractor has two antifreeze (block and rad hose ) heaters plus battery maintainer, all on the same cord. If its going down much colder then I might even throw an old blanket over the hood to stop some windchill. This can make a big difference with a marginal heater, even indoors....
While the propane heater will heat the air in the garage quickly, it will take hours for that heat to soak into the engine block and oil....