From a couple of searches on this site, this is what I've read:

MX-810: about a week

MX-900: "months" (the only one with batteries)

My thought is that the color lcd of the 980 will make its charge life much less than the 950....the spec sheet says that 980 will have 120 minutes of continuous usage....maybe this will make the 950 run less than one week....so the 980 will be for a couple of days?

Does anyone know of charge life or the relative charge life of the 950 and 980?

(Without stating the obvious, the charge/battery life will depend on frequency of usage and backlight settings, but maybe we can still make comparisons based on "average" user experience)