Lamp is fully charged now
Check if the light works on all three levels of brightness. If it does, your lamp is ready to be used normally. Use your lamp in one of the different light settings, and compare it to the time stated in the instruction manual or packaging. Overtime, batteries degrade and will lose capacity to hold charge for as long as when they were new. While this is normal, it is possible to replace batteries to have 100% capacity once again.
Is the issue still there?