The 1200mAh Batteries
Any news on the 1200's yet?
Well, yes and no. Here's the update: Actually, the only 1200s I could find are in the AA size, which is much larger than the AAA required by i-SOBOT. I checked numerous sources and it was all the same. The largest capacity AAA batteries were all 900mAh - in the same nickel metal hydride technology.
So my solution was to buy more sets of the 900 AAAs. So now, along with the originals, my humanoid has a total of 13 batteries which makes 4 sets and one extra battery for good luck. This has worked perfect, but the next thing I want is an extra charger so more than one set can charge at a time. This won't be a problem, as the AAA 900mAh batteries are also packaged as "two batteries along with a charger." The cost appears reasonable.
Another surprise, when setting up a new Asian robotics laboratory, I came across the 1200mAh AA batteries! There's at least 4 of these, and probably another 4 hiding in a box somewhere, so it may be possible to develop some kind of battery attachment in spite of the larger physical battery size. If I have any positive results on this, a posting will follow.
Additional Battery Info
For some additional information, the battery solution for the Parallax Penguin robot was to use two of the CR123 batteries. These really pack a lot of power into a small package, and the physical size is fatter around but more stout in height. By matching the combined voltages for the i-SOBOT requirement, an interesting and useful battery pack may be achieved. Plus, these batteries could set partially inside the existing front chest battery cavity for maximum space utilization and to minimize influences on balance and posture.