While changing over to optima yellow top battery I connected a booster battery to the positive post under the hood beneath the fuse box cover. I was sure to connect red positive to pos. and black to bright bolt on converter. I spent probably an hour making the change out and then started the car. Every thing went well. I unhooked the booster from under the hood and expected to find the memories on radio intact. Didn't happen. Lost the programed stations and the reverse beeper is back on. I checked booster and it was at full charge. What did I do wrong??? I had used that booster twice in the same manner when I had deleted OEM batt. So I know I hooked it up right, By the way the Oem battery is like new and holds a charge for a week at over 12.3 I only changed it because I have added an electric wheelchair liftThat pulls more amps leaving battery too low to start car. Anybody need one