After discussion on NewtoTalk, I decided to try prepare custom battery pack for eMate 300. The original one contain 4 AA NiMH 1.2V cells.

I did some research and I found plastic holder for AA batteries.

Adaptation of this holder should not be a problem. What I need to do is:

  • solder positive and negative wires to connector from original eMate 300 battery
  • stick thermistor (temperature sensor) somewhere near new NiMH cells

That custom battery will be much better, because in case of NiMH cells wear, it is possible to replace them quickly, without desoldering or cutting. The second advantage is the possibility of using NiMH cells with a larger capacity, which will extend the eMate 300 operating time. Of course, time needed to charge battery will be longer, but this is not a problem at all. At the end, that custom battery will cost much less that original replacement. So, only benefits 🙂