Li batts may be better for some things(many actually) but NOT
NIMH is the way for our Streamlight to go. Li batting may be better at some things (actually a lot), but it's not! A Streamlight I have been using NiMH bats in my Streamlight for many years and have always been satisfied. One of mine was over five years old, and it didn't seem to take long to recharge, so I went to Amazon to replace it. In doing so, I noticed that they are now selling Li replacement rackets. I think they sound good, lighter, and have no memory effect (although I never really noticed the memory effects of my past Ni-MH batteries, because I tend to run them until they darken and keep charging them), I can use my existing charger. The main problem with my replacement of Li is that you definitely have it! There is no warning that the battery is running out (I am now using a light-emitting diode Streamlight). One second is on, the next is on. For the first few times (even now) I was worried that my LED had burned out and noticed that if this happened, no matter how long I sat, the LI would not light up for a few more seconds, and it would go out until you recharged it. This is my main complaint about Li in our Streamlight s, it is absolutely worthless to the emergency flashlight, it will run out without warning, it will go out when it runs out, and it will never be turned on again until it is recharged. Compare it to NiMH, for example, the NiMH, sold here will give you a few seconds of dimming time as a warning that it will die, even after it dies, all you have to do is shut it down for about 30 seconds, and when you reopen it, it will give you a few more seconds.