I am looking for a cost-effective solution to re-fill my DuraTracs after airing down for off road. I only wheel a couple times a year, so permanent onboard air isn't a necessity (nor is the expense). Rather, I'd prefer to go with something I can toss in the back of the Jeep. Are there any 12V options or options that would work with the 110 outlet in my Jeep? I look forward to your recommendations.