The 2004–2007 Chevrolet Silverado PHT was a full-size pickup truck. Chevrolet was able to get a 10% efficiency improvement by shutting down and restarting the engine on demand and using regenerative braking. The electrical energy was used only to drive accessories such as power steering. The GM PHT used a 42 volt system via three 12 volt vented lead acid batteries connected in series (36V total) to supply the power needed for the startup motor, as well as to power the electronic accessories.