DieHard 71219 Battery Charger and Maintainer for $16.99. Order online for in-store pickup at Kmart to lock in the price and save on shipping.  Otherwise, shipping is $6.50 for a total of $23.49 shipped. Here is a screenshot for your reference.  This battery charger/maintainer features a float mode monitoring for 6 and 12 volt batteries, and [...]