u-blox XPLR-HPG-1 User Manual page 15

Power from the USB-C connectors go through a dual-input linear Li+/Li-Poly battery charger. The
charger can use the power sources available (USB-C connectors and battery) to supply the
consumption of the board and the additional Click boards. The output of the charger circuit is used by
a DC-to-DC boost converter that is responsible for supplying 5 V to the board. There is also a linear
power supply that is responsible for supplying the 3.3 V.
2.1.2.1 Battery charger
XPLR-HPG-1 is equipped with a MAXIM MAX8934 dual-input linear charger for Li+/Li-Poly 1 cell
battery. The charger is supplied by either the USB-C UART (J6_2) or the USB-C NORA (J6_1). If both
USB-C are connected, the USB UART takes precedence (with regards to power supply). Input current
is limited to 2 A and the charging current is limited to 1.35 A. When the input current is reached, first
the battery charging current is limited, then the charging stops, and if the power demand is even
greater, the battery is connected to support the load.
2.1.2.2 Battery
An unprotected, flat top 18650 (one cell) Li-Ion/Li-poly battery can be used for powering up the XPLR-
HPG-1. Insert the battery in the BATT1 battery holder. Polarity of the battery should follow the
silkscreen of the PCB. See also
whenever there is excessive power to the system. The yellow "CHARGE" LED is lit when battery is
charging.
⚠
XPLR-HPG-1 is designed to work exclusively with 18650 cells that feature an "unprotected, flat
top" configuration, for example, the LG HG2 INR18650, Samsung INR18650 or other variants. It is
advisable to use Li-Ion batteries (rechargeable) Implementing an incompatible cell can seriously
damage both the XPLR-HPG-1 kit itself and the battery unit. The battery is not included in the
XPLR-HPG-1 kit.
Figure 9: Battery holder, polarity
Figure 10: Battery LEDs
UBX-23000692 - R01
C1-Public
Figure 9. The battery is charged whenever a USB-C is connected and
Hardware description
XPLR-HPG-1 - User guide
Page 15 of 37