I nearly posted a similar question just a few days ago. I'm using 2 sets of Sony M style batteries made by Energizer and I'm able to get 3-4 hours out them during heavy shooting with my Valeo 22 wi. This really isn't acceptable but I've yet to find alternative sources of batteries.
Thank you for your information, I have the same set of batteries and I have the same opinion. Often I am short of batteries. I need batteries for 10 hours of no stoping work. I checked the xtreme 20, quantum turbo 2x2 and the Lumedyne HV Ultracycler. I will apreciate if anybody had experience with any of those mentioned.