Hi..again.
Good to here your're following thru on the battery pack idea. I'm not sure exactly what your're looking for. But i think
this may be it. If you do build your own battery pack, check my geocities page in my pda(if you're unsure with soldering irons) also do not to hesistate to pm if you need help. I would suggest a home built one, (i own both) because the pelican power bricks have a tendancy to overheat and stop working according to some psp forums.