What is the max safe temperature for a nimh battery???

To kind of answer my own question.....

After several runs on my 8 cell gp3300 battery its defiantly getting weaker. I mean it still takes almost 3300mah of charge its that its less punchy than my 7 cell gp3300 pack and about the same power as my 6 cell pack. I remeber the first couple of times using the 8 cell pack it was crazy fast.

I think the 170 - 180F+ temps hurt the 8 cell battery and eventually took its punch away. Anyway on the same gearing my 6 cell pack saw temps in the 120F's, 7 cell was in the 140-150F's. I think I am going to lower the pinion gear two teeth and try the 8 cell pack again.