ARE omptima batt. any good...i have one hooked up..{were car battery was} and every time i put the alrm on the batt. goes down in the same night. is it cause the flashing lights that blink when the alrms off?...ive bought 2 and they do the same thing...so finnaly i went to napa and bougth a bigger one and i can keep the alarm on for days and it wont die??..what is the batt. good for?