I2current

I2Current powerboard

The Raison d'être of this board is to be a powerful, extensible, and affordable replacement for hotglueing a random powerbank into your next portable small-scale electronic project.

The largest benefit comes from the I2C interface - If, for example, a Raspberry Pi is powered with this board, it can actually check the battery state, if DC-jack is currently charging the device, or even see the power draw of other peripherals connected to this system.

The board is most useful for powering devices requiring peak power draw between 15W-60W.

For devices requiring less power, the cost overhead becomes a bit too much - alternative solutions on aliexpress, albeit not as much versatile, can cost less than $3 (this board costs ~$10, ordering 20 units from JLCPCB).

Sub-components

BQ25792 Li-Ion charger

Specs:

• 3.6-24V input, max 3A (realistically, ~60W)
• Input voltage independent from battery pack (buck-boost built-in)
• Input from USB-C and/or DC barrel jack.
• Can provide up to 3.33A@20V output to the same USB-C port
• can work with 1S-4S (cells in series)
• output current 5A (with 4 cells (~16V), up to ~80W output)
• Works properly without battery pack too (can work as buck-boost power supply)
• Many parameters configurable via i2c
• Various battery/input/output voltages/currents readout

This charger is incredibly universal, costing around 1$ it provides versatility for many types of projects.

TPS56637 5V output step-down converter

It can provide up to 6A (30W) on output. However, it requires atleast 2S packet to be usable.

MT2492 3V3 DC-DC

This converter supports optional built-in ESP32-C3 controller, and can also be accesed via output pins

SPX3819M5-L-3-3 3V3 LDO

This low-power stabilizer provides power to onboard devices and some circuitry. It cannot be turned off, in contrast to 2 other converters.

FUSB302B Power Delivery controller

This device is controlled via i2c, and can be used to negotiate up to 5A/20V from compatible USB-C chargers.

Arduino library is available.

Connectors

Output 2.54 connector

This connector has been designed for low-profile goldpin socket connector (the male header actually goes through the holes in the PCB)

Shield can be designed, utilizing this connector.

Picoblade connector

This connector is dedicated for devices, where a "master" board sits somewhere else in the system.

Battery connector

• Battery input
• NTC resistor input (every battery pack should contain one, more on that later)
• GND
• Battery output (coming from BQ charger, provides stable voltage when baterry is depleated or missing)
• GLOB_OFF (pin for external power-off switch)
• VDC_IN (same as from barrel jack input)

More to come...

this board has many more fun quirks - I'll describe more details at a later date.

• optional mini front panel with OLED
• Passive-PoE input
• standalone 4-channel WLED controller
• USB data lanes passthrough for 2 connectors and built-in ESP32

Todo - document:

• Li-ion safety guide
• USB passthrough
• GLOB_OFF usage
• Pinout description for every connector
• 1S-4S config and limitations

Sponsors

Developent of this board is supported by Clue.lamp.

Check them out, the device looks really nice, and utilizes state-of-the-art electronic design for both wired and wireless usage :)