weak battery

our 97 catera has a hard time starting up. when it turns over its like the battery is dead. but iput a battery charger on it and it says the battery is fully charged. i dont have a battery tester so do you think the battery is dead or is it some other electrical problem?

You need a voltmeter to check the battery static.
Then check it when you crank.
Then check it when it is running.
Then check it when it is running with headlights, blower motor, etc on.
Or go to auto parts store. They will normally test your battery and alternator for free.

battery went bad thanks.