Agreed, an onboard charger permanently wired to the battery terminals just needs to be plugged in once in a while. I've installed them on the three vehicles I look after. They can be a lifesaver when the car sits for a few days.you gotta drive it enough to keep it charged + the smallish battery adds to the other drains. sisters 18 impreza battery died in 3 years!!!. get a charger + USE IT!!