Do the batteries have charge indicators? If so, what do they show?
I have the same screwdriver manufactured in 2011 that just keeps working, except the batteries have broken... I thought it was the charger once, so I bought a new one, but it turned out to be the battery that time too...
Sure, the batteries probably don't last anymore, it usually doesn't pay off to buy new batteries. Costs as much as a new machine. 14 volts aren't so common today.