Power

Help specific to powering your Unexpected Maker boards

Devices powered from the 2nd LDO power down when the ESP32 goes into deep sleepLDO 2 is tied to both a user controllable IO and VDD for the Flash/PSRAM, so when the ESP32-S2 & ESP32-S3 goes into deep sleep, it automatically shuts down LDO 2 for you, so you don't have to remember to do it yourself.

What voltage range can the 5V pin accept and is it an input and output?The 5V pin on your board is an in and out pin. As an input, it will accept a voltage range between 4.8V and 5.2V. Please do not connect any power source over 5.2V to the 5V pin and please do not connect your battery to the 5V pin. It is for a 5V power source only.

How fast will my battery charge?The battery charge rate on all Unexpected Maker boards is set to 330mA based on the 3K3 charge resistor used.

Sometimes my battery doesn't start charging when I plug it inIf 5V power is connected to the board before the battery is plugged in, the battery might not begin charging.

Powering your board from batteryAll Unexpected Maker development boards support powering via single-cell Lithium Polymer batteries with charging capability through USB or external 5V sources.

Can I connect my battery to the 3V3 pin?No, absolutely not.

Can I connect my battery to the 5V pin?No.

The ORANGE charge LED blinks when no battery is connectedThe charge IC can't tell the difference between a full battery and no battery, so it cycles between trying to charge and not charge.

Why don't I get 5V output on the 5V pin when running off battery?The 5V pin can only produce 5V if there is a 5V source connected to the board via the USB connector. There is no boost/step-up converter on these boards to provide 5V from the VBAT input.

Can I power my board from the 3V3 pin?Yes, you can power an Unexpected Maker board using the 3V3 pin if you have an external 3V3 power supply available. However, there are important restrictions.

The RED power LED doesn't light up when running off batteryThis is by design, not a malfunction.

How do I read the battery voltage?Each Unexpected Maker board includes an IO pin connected to a voltage divider on the battery, allowing you to read an approximation of remaining battery voltage. The specific IO pin varies by board -- consult your board's pinout card for details.

I've set my RGB LED to black/clear and it's still drawing current?All RGB LEDs have a quiescent current of between 500uA and 1mA, so even setting them to display nothing still cost battery power.

How many Amps can I pull through the USB to the 5V pin?The short answer is 500mA sustained. You can pull up to 1A for short periods of time before the reverse back-feed diode starts to overheat and could be damaged. Anything over 1A will likely kill the diode very quickly.