T3 battery... I put (inside) a 1700 mAh! It rocks!!! Hi guys! I bought an almost new T3, but come on... the 900 mAh it has it is terrible!!! It lasts just few hours. The available 'Palm To Go' it is fine...but still just an annoying add-on.... and so the external batteries... I browse the WHOLE internet and found no idea. But hear what I have discovered!!!! :-D You can fit 2 batteries in parallel fo the Palm m500 (that are very cheap in Ebay). They are 850mAh each, 3,7 volts, and they have a protection circuit each. Just join the red cables, and the black ones, using the dungle of the original battery of the Tungsten T3. Doing so you will have a very thin 1700mAh battery!! It is no invention at all, See some batteries for Tungsten C, sometimes is made using two batteries like this. (and they are 1700 mAh) The next operations are very easy. You should modify a bit the inside (just because you need 3-4 mmm more). I got shorter the Palm pen canal 35 mm, so the pen should also be cut. It will be held by creating a small knob with a knife and some glue (it is easy and works). I also added some cm of wire for the wiring. Then you close the Tungsten!! And it works FANTASTICALLY!!! It lasts ages!! It ROCKS!!! And I am quite sure that exists for Palm m500-m515 ecc. some 1000 mAh batteries so everything can be even better. reaching 2000mAh It is like having an Ipod... And aesthetically and functionally is perfect. Even the weight is more or less the same. It seems to me that the only reason they put such an awful battery of 900mAh it is that they wanted to insert that stylish pen... Shorted with the same telescopic system it is even better. I am sorry I had no camera to document what I have done, because it is really INCREDIBLE!! But I have done a little video 7 MB here you can watch... Hope you will find it useful. In this site I learned a lot, that's why I am sharing this with you. I wish you the best.