Thankx ; that gives me a little more clarity on the situation. Having recently come from the alkaline primary world into new high tech torch world with Lions and Nimhs its taking a little time to wrap my head around the new parameters. I was worried that i would use my light and then all of a sudden it goes dim and the battery is already damaged and i guess that could happen in certain situations and me as a light user ,tending to be in moonlight or low mode quite a bit, so i guess i need to figure out my general usage and recharge appropriately before it gets too low.
Yes, it's always the best to understand what is happening

Unfortunately most of current flashlights are not as worry-free as I would like them to be. You should note though that the batteries tend to be pretty tolerant to abuse. They should not be overdischarged but if they are, and they are not kept discharged for too long and to an extremely low level, they go back to life. They may lose some capacity, their life can be shortened but usually they won't be completely dead. It's not a good idea to overdischarge batteries but usually it doesn't destroy them either.
EDIT: I think that for a normal use it means that one should be worried mostly about lower levels, as you wrote. If the light dims on high, the battery may be overdischarged a bit but it can be easily seen and when the light is turned off the voltage will rebound and probably nothing wrong will happen. In lower modes what is dangerous is the possibility that the user is unaware of the flashlight pulling the current from an already overdischarged battery, damaging it this way. It should be investigated if such a possibility for a particular light exists and if it does, this situation should be avoided.