Optima Yellow top works great in Protons

VT, a battery buddy is an electronic device that is installed in series with the positive lead on the battery. If the voltage drops too low, the battery buddy isolates the battery from the electrical system (shuts down). Theoretically it shuts off with just enough juice left to restart the vehicle. You have to actually pop the hood and push a button on the battery buddy to start the car if it's been tripped.