1999 Chevy S10 battery has been charged only getting 9volt to gauge in side car?

The gauge inside is telling you how many volts your alternator is putting out, not yoru battery. Go have your alternator tested to see if it is putting out 14 volts or more...........if not, you are drawing more current out of the battery then what the alternator is replacing and you are going to end up with another dead battery. They can test alternators at Autozone for free or you can go get a multi meter and test it yourself. Have the alternator checked.