I have both a Battery Tender and the Optimate 3. I got the Optimate pigtails so hook up is a snap. I keep the Tender on my RZR during the winter (I use it for plowing snow, keeps the battery up to snuff) since the winch draws so much juice. I plug in the Optimate to the Wing about once a month. C17 is right about the cost of the Optimate, but with the refresh capability, it's well worth the buy-in.