Big Nugget v2 - 5V 4A

Regular price $80.00 Sale

Sorry, this product is discontinued!

* Comes with 4 18650 Li-Ion batteries! *


The Big Nugget is best for high current projects needing long runtime from a battery source.  It's great for Raspberry Pi, BeagleBone, Arduino, IoT, and more.

It can power a Raspberry Pi drawing 1A for about 7 hours.  An optional header allows you to connect larger batteries for extended runtime.

The output is powered from the input source.  If there is no input, then it is power from the batteries.  There is no downtime when switching from the input to the batteries. 

I2C is available for checking battery capacity and voltage.  It can also be used for adjusting settings such as max charge rate and input current limit.

The Big Nugget v2 is based on the Texas Instruments BQ25703A power management IC and the AOS AOZ2261 buck regulator.



  • 5.1VDC Output
  • 4A Max continuous output
  • 0mA - 5000mA max charge rate (default 2000mA)
  • 3.9V - 14V input
  • 90%+ Efficiency when running from Input Source
  • 85%+ Efficiency when running from battery
  • 60μA sleep current


 LED  Status
Green ON
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


Changes from Version 1

  • Powered by 4 18650 Li-Ion Batteries (up from 1 battery)
  • 4 USB type A outputs (up from 2)
  • 4 cell battery management and balancing



Why don't I use a mobile power bank instead?

A power bank (for charging your phone on the go) has many limitations.

  • Limited output current
  • Cuts off power if your device is drawing less than 500mA for too long
  • Cannot charge its internal battery while providing power to your device

Is a battery required?

No.  This power supply will work without a battery.

How much current can the USB A output?

Up to 4A continuous.  There is no negotiation for this output current.  Any device is capable of drawing up 4A, so use with caution.  

Will the battery charge when the power supply is off?

Yes.  The power switch will disable the output but still allow for charging.  Disabling charging can be done via I2C.


Can I connect two or more devices to the output?

Yes.  You can connect as many devices to the output as you'd like, provided they do not exceed the maximum output current of 4A.

Can I connect two or more batteries in parallel?

Yes, at your own risk.  Use high quality batteries from the same manufacturer.

What are the power supply requirements?

We recommend using a 12VDC 3A power supply.  Ideally, this can provide a minimum of 4A output while charging the batteries at 2A.

You can connect any power source between 3.9V and 14VDC. 

The minimum amperage of your power source depends on the max charge current of the battery and the max current of your project.  If your project draws too much current and the voltage at the input droops more than 600mV, the power supply will automatically reduce the charge rate of the battery.  If your project draws even more current, the battery will deliver supplemental power.