Little Nugget v2 - 5V 2A
This 5 Volt 2 Amp power supply runs off a single Li-Ion cell and is charged via micro USB.
The input can provide power to the output and charge the battery simultaneously. When the input power is removed, the battery supplies power to the output. There is no downtime during this switch.
Little Nugget v2 makes some improvements over v1, including 2 USB type A outputs and can provide power from the micro USB input without a battery connected.
- 5VDC output
- 4A peak output (100ms max)
- 2A continuous output
- 90%+ efficiency
- 2μA sleep current
- Micro USB charge input
- Micro JST Connector for Single Cell Li-Ion
- 500mA max charge rate
- Minimum recommended battery capacity - 500mAh
|Green and Slow Blinking Red||ON, battery low (<30%)|
|Green and Fast Blinking Red||ON, battery critical (<10%)|
|Glowing Green||ON, charging|
|Glowing Red||OFF, charging|
|Red||OFF, fully charged|
|Efficiency (LEDs off, Vbat = 3.6V)||Output Current|
Do I need a battery to use this power supply?
No. Unlike Little Nugget v1, this power supply will work without a battery.
What does the LED switch do?
This switch is for disabling the LEDs. The LEDs draw a maximum of 1.67mA each. In some low power applications, disabling the LEDs may increase battery life significantly.
Can I charge with something besides microUSB?
Yes, if you want to add another source, you can directly solder any source between 3.75VDC to 7VDC. See the schematic for where to make solder connections.
Can I change the max charge current?
Yes. You'll have to remove replace resistor R5. The charge current can be anywhere from 0mA to 500mA. The formula for R5 is Max Charge Current (mA) = 1000 / R. The standard value for R5 is 2kΩ.
Why won't my power supply turn on?
See if the LED switch is on. The power supply may be on even though the LEDs are disabled.
Will the battery charge while the power supply is off?
Yes. The power switch will disable the output, but still allow the battery to charge.