Correct me if i am wrong, but the 3 1.5v battery on psp idea have came out a while ago, but acidmods were the first ive saw to have it more internalize. Ive see it where someone did the same thing but had the battery plastic thing making it extremely bulky.
look like the company did that to cut cost for the batteries, because y would u need replaceable aaa batteries on a service mods battery.