Is there anything an Arduino can't do? Well, for one, most of them
can't be powered directly from a 3.7V LiPo battery; much less charge
and monitor that battery. The LiPower Shield takes care of this by
combining the functionality of two of our favorite battery power
boards: the Power Cell and the Fuel Gauge.
The LiPower Shield allows you to connect a 3.7V single cell Lithium
polymer battery which it will boost up to 5V and connect to the
Arduino board's 5V pin. The on-board MAX17043G+U IC is connected to
the I2C lines (A4 and A5) so that your project can monitor it's own
power supply. The configurable alert interrupt pin on the MAX17043G+U
IC is broken out to D3 which will activate when the LiPo gets to 32%
The charging circuit is configured to charge the LiPo at 100mA but by
adding a resistor to the supplied through-holes you can boost this to
500mA. There is a mini-USB port on the shield which allows you to
charge the battery from a USB power source or you can supply a
separate regulated 5V source on the "charge" header.
Note: We've decided to leave the power indicator LED (LED1) and its
current limiting resistor (R3) off this board, as they were producing
a significant drain on the battery. Please be aware that your board
will have a few, shiny, unpopulated pads.
Note: There is a known hardware bug that will allow the LiPo to
discharge below the point where the charging circuit will revive it.
Thanks to the on-board fuel gauge, however, some clever programming
could keep your project from draining the battery as it gets too low.
We ship this shield with a free set of stackable headers!…more