get a trickle charger.....i use a CTEK charger + quick charge accessory. It runs a line from your + and - to a handy little dongle , which the carger hooks up to. Plug it in when you leave the car for more than a few days....topit up and keeps in in top condition.


Anyway , tired another battery ? Are the terminals 100% tight ?
The supercharge may be totally dead and cant be revived - dont try and charge it , it may blow up.