I'd never put one in a daily driver or even an offroad vehicle. These must be expensive as all hell, charging circuit built in or requiring an entirely different charging system. Constant current is close enough to claim but not constant voltage. They probably use a built in voltage regulator. Personally I'd shy away from the daily driver and explosive puncture issues of trying to sell what I'd bet is a 300-400 bean battery. What we really need is better charging, not batteries.