Jumper shown above is selected for 3.3V.
The board comes with 5V enabled (center pad and 5V connected). If you want to use
3.3V, clear the solder blob over the 5V pad and move it to the 3.3V pad (center pad
and 3.3V connected). The safest way to do this is with some solder wick, or just turn
your soldering iron down to a lower temp and move the solder blob with the iron's tip.
Step 3
When you connect your battery to the Powercell, you can power your
system/load/Arduino with 3.3 or 5V. However, there are some control mechanisms
that you must not overlook.
There are two main modes you can use (there are other configurations):
Charge Mode:
If you want to charge your battery or just let you system standby, with no power draw
from the battery, you must pull the EN pin to GND (by default it is pulled high, ON).
The EN pin turns the regulator portion of the circuit ON and OFF. Even if you have
only your battery connected, you should still connect EN to GND.
Power Mode:
When you need to power your circuit, you can leave EN floating (no connection) or
pull it to VCC. If you want to have USB charging as well, that is fine, it won't hurt
anything.
Here is an example setup:
A good way to use the EN pin is to connect a SPDT switch. This way, you can turn
everything OFF and ON.
