DIAGNOSIS Probably not. The FUEL hammer drill is significantly more powerful than older non-FUEL M18 models. That power comes from drawing more amps from the battery under load, which can drain it faster if you're using it hard.
FIX First, check your battery's health. Is it an old battery you're using with a new tool? Older batteries have less capacity. Try a newer, high-capacity battery (like an XC5.0 or HO) and see if runtime improves. Second, consider your use. Are you using hammer mode a lot? That's the highest power-draw function. Are you drilling large holes or driving big lag bolts in low gear? That's also high draw. The tool is working correctly, it's just using the available power.
IF THAT DIDN'T WORK If you've tried a known-good, fresh battery and runtime is still abysmal (like 5 minutes on a simple task), there could be an internal short or a binding gear creating excessive drag, making the motor work overtime. Listen for any unusual whining or feel for heat when running with no load. If present, it may need service.
HEADS UP Runtime is a trade-off for power. The FUEL technology is about delivering maximum performance, not necessarily maximum runtime from a given battery. For long tasks, plan on having multiple batteries. Also, make sure you're using the right tool for the job—the hammer drill is overkill for small screw driving, where an impact driver or smaller drill would be more efficient and save battery.