I try to use NiMH as much as possible, but there are still a number of applications for which alkaline is superior. First, alkaline usually has more energy. S

I try to use NiMH as much as possible, but there are still a number of applications for which alkaline is superior. First, alkaline usually has more energy. Second, the voltage is more predictable. For devices like door locks that are battery powered and can detect a low battery, alkaline works great. NiMH has lower voltage and looks dead before it is. And lithium (not lithium ion) batteries have a very flat voltage curve and tend to die rather suddenly almost before the device can detect they're end-of-life.