just got an eGo Twist battery to supplement the 2 I got 3yrs ago in a starter pack. when I plug it in to charge, the light on the batt flashes 4-5 times and the light on the charger lights red, same as my origs. but, with this one the red light blinks every 5secs or so. don't want to leave it plugged in if this means something bad. any advice? thx