I have the same problem with my winch draining the battery after a long pull. All the connections are fine and the batter is brand new 1 month. As mentioned before those batteries are small and most winches suck a ton of amperage. I have to keep my rev'ed right up to maintain winching power.

 

Use a battery tender. Top-off the battery.

I never have a prob snowplowing. Steady use of the winch at night up and down, running front lights, rear work lights, and blinking strobe.

I plug mine in only once a month.

 

I think something is wrong with your winch. I have used mine several times when out and about and never had the battery go down on me.

 

i have many times. i plow 1 100ft drive and another 50ft drive. both drain the battery. but then again i have other things on as well. but soon as my cooling fan kicks in. and im useing the 3000lb winch it really kills the battery. but then i may have had a bad battery since it froze last week, and i got it warranty'd last week along with my solinoid. on my 335 i only had a 1500lb winch. never had a problem on that. evon when useing the hand warmers. i still want to get a higher amp battery..... so when im driveing it will charge the battery some. but right now i dont fel like paying over a $100 for a battery.

 

I'd doubt a better alternator is going to solve anything. When you are using the winch, the alternator is not even a drop in the bucket, and all it can do is recharge the battery a little faster once it's down. The real answer is to add another battery. If you are in the type of area you say, and depend on the winch, then I'd add a car battery, or even remove your current battery and install two car batteries. That might sound insane to some of you, but if you truly use the ATV as a "utility" ATV, then power (and the winch especially) is something that you want when you need it, where you need it. If you are not jumping hills and getting into 3 feet of mud for fun, but you DO need to pull something 300 feet up the side of a cliff from time to time, then extra battery power is the way to go.

I will just add this. I have a standard battery in mine, and I have lifted it off the ground (just a few inches) and set it back down at least 5 times using the winch hooked to an overhead beam while I was working on it, never cranking it once, and then when I was done, it cranked right up like always. It is impressive how much power those little guys can provide.

 

Try a battery (tender/maintainer). Be certain this device you purchase will de-sulhate your battery plates.This is key,However your plates may be to far sulphated to repair. If this be the case,you'll be in need of a new battery. Purchase this batt. tender anyhow to prolong the battery's life on anything you use around the house or shop that is of 12 volts. An alternater or stator system are only (trickle chargers)and certainly cannot keep up to the demands of continuous winching,heated grips, higher current light bulbs,etc. If you do the math of current draw verses input charge you will see external charging is absolutely necessary.

 

Check how many amps your winch draws on load. May be something wrong with the winch pulling too much amps.