Features 

• Dual output
• Secondary regulator has three voltages (0, 2.5, 3.3), and can be changed dynamically.
• Fused battery (resetable)
• Charger and fuel gauge are both i2c
• Integrated 4-bit level-shifter (i2c capable)
• Accepts up to 20v input
• 2.54 headers
• Single-sided assembly for easy thermal-relief

Constraints

• Battery must be Li-ion chemistry. 
• Primary regulator is always on and fixed at a 3.3v output. 
• No single regulator may provide more than 1.8A, and the module's maximum output wattage is 4.2 watts. See below. 

Charge and discharge rate on the battery must not exceed 1A, or the internal sense resistor in the fuel gauge will burn out. There is a resetable fuse to prevent damage, but this forms the limit on the module's practical output rating. However, the charger IC can handle up to a 20v input, and could conceivably draw more than the module's maximum output from the input source as it charges and powers the load. Fuse accordingly. :-)