JCI Predicts Growth in Micro-Hybrids

Johnson Controls Inc. is developing a micro-hybrid system that uses a 48-volt lithium battery for electric drive and a 12-volt lead-acid battery to supply power for light accessories.

The 48-volt battery enables a mild hybrid that uses energy captured from regenerative braking to power the engine's stop-start system, plus high-load accessories such as air conditioning and an active chassis. The 12-volt unit drives interior lighting and audio/entertainment.

In operation, the combination is similar to General Motors Co.'s mild hybrid on the current Malibu and LaCrosse models. But the 48-volt lithium-ion battery promises expanded capabilities, says Brian Kesseler, vice president and president of JCI's Power Systems division.

Compared to a full hybrid system, the JCI micro-hybrid will deliver most of the capability of a full hybrid powertrain but cost only a few hundred dollars, Kesseler notes.

JCI's system includes the dual-voltage battery system, a new motor/generator, and a DC-DC bridge that enables the generator to recharge the 12-volt battery. The company says the system has been sold to an undisclosed carmaker.

JCI also anticipates continuing growth in simplified stop-start systems that use lead-acid batteries. GM announced earlier this month that it was converting to less expensive lead-acid batteries for the 2014 Chevrolet Malibu's stop-start system.