Try
7dayshop.com - Online shopping made easy !. They sell normal batteries (I think) and also 2,200 mAh extended batteries for about £7. They come with a replacement back to take the larger battery and the Axim will sit in the cradle with no problems. They will also charge in the back of the cradle. The are excellent batteries.
I was so pleased with mine that I bought two!!
If you do go for the extended battery (which I certainly recommend) then you will need an extended battery case (if you use a case, of course). I recommend the Sena case from cases.com. They give a discount to Aximsite members and ship from the US to the UK with not troubles. The shippping costs about $13 by air mail. The Sena is the only case which lets you sit the Axim in its cradle without having to take it out of the case, which saves a great deal of hassle.
Hope this helps.
