Hey Gang, I just got a Bochure from OPTIMA on there Commercial Yellow Top C31 Battery. . These things are Recommended for 18 Wheelers along with Heavy Equipment Emergency Vehicles ... What I'm wondering is, A. Do any of our TDR People Sell these things? B. Has anyone tried these Commerical Battery's? I'm thinking maybe ONE Battery MIght Run the Truck instead of Two... Here's there E- Mail address (SALES@OPTIMABATTERIES. COM) C 31 is the Commerical UNIT. . Radar Doc.