RAK4600 + RAK5005 high power consumption

Hi all, thank you for reading this.

Issue: I’m working with a RAK4600 + RAK5005 baseboard and I’d like to verify the low power mode current draw.

Setup: The baseboard is fed by a USB cable, which I modified so I can put a shunt resistor in series with it. To calculate the current draw I measure the voltage drop over the shunt.

Observation: After boot, I measure about 6mA. As soon as I open the Serial port tool the current draw increases to about 7.8mA. I then send the AT command to put it into sleep, but the measured current draw only drops a little to about 7.2mA. What is happening here?

I read that when a USB cable is connected, the board might draw more power. Is this because of the USB to TTL converter chip? What is the recommended approach of measuring power consumption? I do not have a lipo battery and the datasheet says that the supply voltage on the bat connector may not exceed 4.2V.

Thank you in advance,


Hello Daan,

If you supply over the USB, you constantly supply the USB chip (CH340), the battery charger (even if no battery is connected it will use little current) and the voltage regulator.

The only way to get around these components is to supply over the battery connector.

1 Like

Hello Bernd,

Thank you for the info. I’ll test it later than by supplying the battery connector with the correct voltage.

Hi @Daan ,

Just to add on this. If you want to measure the current consumption, use BLE interface instead of USB when sending sleep command at+set_config=device:sleep:1

If you use USB, there a big chance that the RAK4600 will wake up because the UART lines of the USB-UART chip will be in an unpredictable states. Take note that during sleep, RX pin is internally pull-down and any high trigger edge signal on the RX pin will wake up the RAK4600.

RAK4600 BLE Interface guide - RAK4600 Module Quick Start Guide | RAKwireless Documentation Center