I am a newbie here. I want to power the Grove shield and the GPRS shield with the LiPo battery pack in the stalker. (and not through the USB5V power.)
So, is it ok for me to connect the LiPo battery pack directly to the USB5V so that it can provide power to the Grove shield and the GPRS shield.
Also, is the connection ok, if I put the stalker out so that the solar pack is powering on the battery as well as the battery is connected to USB5V?
Thanks.
Hi there 
The GPRS shield work voltage is 5V , so it will not work if you just power 3.7v(Lipo battery pack)
Deray
You need this: seeedstudio.com/depot/solar- … th=132_134
Thanks for your replies, and you are right that with 3.7V, the battery will not be able to power the GPRS. But when the battery is fully charged (4.1V), then I have found that it is able to drive the GPRS shield for some time.
Right now, as I have it, I have the GPRS shield, Grove shield, battery and solar panels, mounted as per the Seeduino stalker configuration.
I have removed the USB5V external supply (removed the UARTsBee), and when I solder a wire connection between the BAT (bottom of the Arduino board) and the USB5V, it was able to power on the GPRS shield and work for some time (till the battery level fell below 4 V). The small time was enough for me to upload the Arduino values to the remote server and serve my purpose! And when the solar panel charges the battery again to its max, I can program the GPRS shield to start working again and send its update.
I took a look at the circuit diagrams, and apparently, it seems to be ok if I connect the BAT output back to USB5V. But I just wanted to make sure in the forum that this was correct and it would not cause damage to the board.