This charger normally is $29.99. It plugs into your cigarette lighter and puts out 1.8 watts. Sku #2771202 even the employees didn't know it was on discount. I use it for my full size van to keep the battery charged in the winter as I don't like driving it the snow. My van also has an electronic rust buster which draws the battery down. I just lay them on the dash and keep the snow off the windshield. Yes, I have 2 in parallel. They work great , I hope this helps someone out.