PowerPC :: IBook G4 12" A1133 Not Powering Up / Not Getting To PMU?

I've inherited an iBook G4 12". Model A1133. It came with a partially charged battery and a known power issue. Initially with the battery partially charged (on another iBook), the machine turned on ok. The battery was not charging, according to the About this Mac and the Coconut Battery application, although the light on the AC adaptor was amber. As the battery became flat, the iBook was no longer able to be turned on. I have reset PMU, PRAM, Opened the Firmware and reset the NVRAM, reseated the battery and tried a host of things suggested on this forum and others to no avail. I have also replaced the DC-in board (no difference, so put the old one back in) and tried a different power adaptor. The battery is as flat as a tack (now occasionally flashing one light when button is pressed) and now there is no chime, fan noise except for an occasional sound which sounds like the hard drive starting then stopping (very faint sound though) when I try to power up the iBook. I was hoping to get an external battery charger to charge the battery as I don't have a spare charged one nor access to a similar working iBook. I live in Australia and have been unable to find one online here. The other thing I have heard on two forums, is that this iBook doesn't have a PRAM battery and therefore cannot start without a powered battery in place. If this is the case, then the issue may be that of just the power not being delivered to the PMU?