If it shows 0 percent after a charge, then the battery is not taking the correct charge. You need a volt meter and hydrometer to test. What battery is in it? 24 or 36 volt? I f you have one bad cell, the truck wont work. You could have a corroded terminal or post. Same result, no power. The truck need to see a higher voltage than what it had when the battery went dead. If you have a 24 volt battery, it needs to see 25.3 before the truck swings the battery meter to 100%. If 36 volts battery, you need 37.6 before the truck re-sets the battery guage to 100%.
If you can lift, load test the battery by working the lift motor. See how much power is lost while lifting. A 24 volt bat might lose 2-3 volts under load maximun. If you drop to 18 volts, you have a bad cell. You can check each cell with a voltmeter on lift. The bad one will show lower than other cells, like 1 volt or less. Also, after working the truck, a hot battery connection indicates resistance. Remove all caps and look for burned connections. There could be a bad solder.