The Digital 400 automatically maximizes battery life and performance with the built-in battery health mode. It also offers a hybrid LED battery charging gauge with LCD display and a quick-set battery type selection for easy operation. And because it recovers discharged batteries that others cannot, this is the maintainer you’ll want in your garage.
Check out reviews for the OPTIMA® Chargers Digital 400 12V Performance Battery Maintainer and Charger at:
TorquedMag.com - OPTIMA Batteries New Digital 400 12v Maintainer/Charger
Mustang Monthly (YouTube) - OPTIMA Digital 400 Review