Lol! You do realize modern tech has blown past that years ago, right? These ain't RC cars Dude. These have air & water-cooling w/complex-multiple pumps or blowers, power control relays, operate on 270 or 360 v, have multiple module controls just to manage charging rates & configurations....the battery assy on a Kona weighs over 960#.....how much do You think a "plug & play" back-up worth even just 30 mi of operation weigh? Oh, & the car won't accept a charge or input if it's in "ready" or "drive" mode& won't move once it's plugged in. That kind of back-up **** has to be engineered in & part of the system, & it is, the vehicles are givin' Ya all She's got Cap'n! They already have warning & crawling along modes, .........