Current limiting parallel battery charging system to enable plug-in or solar power to supplement regenerative braking in hybrid or electric vehicle

Abstract

To provide additional charge storage for an electric vehicle, an additional battery () is connected in parallel with a regenerative braking direct charged battery () through a current limiting circuit (or). The additional battery () is charged by an external charger such as a plug-in charger or a solar panel that supply minimal current to prevent generation of battery heat. Current flows from the additional battery () to the regenerative braking charged batteries () so that both batteries can be charged. However, when excessive charge is drawn to drive the vehicle electric motor (), the current limiter circuit (or) serves to prevent the discharge of additional battery () from creating excessive heat in the additional battery (). Further, when regenerative braking is applied the current limiter circuit (), or a diode buffer () in combination with current limiter (), serves to prevent charging from creating excessive heat in the additional battery () and eliminates the need for a cooling structure in the additional battery ().