I said in the paper " Before every data connection attempt, the WAN signal level and battery power level must be adequate, better than -85 dBm and > 25% respectively." This is not saying you can only use 75% of the battery. Rather, it is saying if you try data connection with less than -85 dBm signal or less than 25 % of battery power, your attempt may fail. To avoide this, you should make sure those meet the minimum before you attempt GPRS connection. There are more reasons why it fails but not discussed by this paper. There is no Microsoft web site explaining why your device fails to connect (for data) even if you see "connected" on the WAN icon. This paper advises you if you are in this situation, disconnect GPRS connection then reconnect. Hope this answers your question.

The current version is still draft as I want more comment for improvement but ok to share with customers as is.

In terms of any feedback, I can appreciate why in an ideal situation the battery should have at least 25% before making the connection attempt, but there could be some concerns if a customer was to interpret this as Motorola Solutions saying that you can only use 75% of your battery;  with that in mind are there any Microsoft websites that the document can refer to in order to explain why this is best practice or somehow make this more palatable for customers?

Hi Hiro, The document looks very useful, is it for internal use only or can we share it with customers? Thanks, Jamie