I rigged a ATV winch in my garage so I could pick dead deer out of the box of my truck...

My Problem is, I need to power the 12 volt motor and all I have is 110 outlets in the garage.

What is my best option to convert the 110v to 12v ?

use a car battery

Kind of started off wrong. Both Harbor Freight and Northern tool sell electric hoists that are about $120. I rigged a trolley and rails for mine to travel on. It lifts,200# single and 400 doubled. Could use a small generator but don't think you want one in you garage.
Would battery charger work? Switch it to fast charge that puts out 10 amps.

Car battery will work but then you are faced with recharging it and now days they don't last more than a year or two.

Sell the ATV winch and use money to buy one on these

https://www.harborfreight.com/440-l...ol-60346.html?_br_psugg_q=electric+hoist

Or buy one of these . Good for10 amps. $25

https://www.amazon.com/AstroAI-Conv...+converter&qid=1660249220&sr=8-7

Ok... more to add.... I read the owners manual. It says, for 500lbs pulling power, I need 12vDC with 15 amps.

1000lbs needs 12vDC with 40 amps.

Don't push it to the limit. Many of them put out a little less than what's on the label. Go with 50 amps. Places like Amazon have all kinds of power converters, 110V to 12V, 40 amps & more. You can find one in the $40 to $50 range that will do it.

buy an inverter.

Buy a boat, use the hand crank boat winch to lift your deer.
Your welcome.

I've got a 3500lb mounted on my wall for lifting deer. I just pull up my riding lawn mower, hook up the alligator clips and use the winch

Do not power a winch, or any electric motor using a battery charger. Best way to burn up both the charger and the consumer.

Halfway off topic, but...
If the spool if full of cable, get rid of all you don't need.
If all it is ever going to do is lift from the floor to the ceiling,
pull cable out until you onlykave one wrap on the drum. Cut it off
a couple inches longer than what's needed to touch the floor.

More wraps on the drum represent leverage against the motor, reducing capacity and
increasing Amp draw.

If you are using a snatch block, be sure to measure using it.

He is lifting a 200# deer. Low draw either way, I'd leave the cable length to keep the higher line speed.

Pulling power is NOT how much it will lift. You'll have to read their definition but usually it's how much rolling weight it will pull up a ramp of some angle. Rolling means it's on wheels with very low drag. If you can find it's lifting weight, it'll tell you a lot more.

Amazon carries a number of 110v to 12v converters for not too much money. Watch the amperage or wattage rating. The ones I've looked at have pretty small wires coming out of them that I'm sure won't handle a winch.