Enabling battery status indicator on NanoVNA

Battery status indicator on the NanoVNA

Most available NanoVNA on the market has a working firmware that works from 50Khz to 900Mhz this version of the firmware doesn’t have the battery status indicator enabled. At the time of this writing there is already a version of firmware that can be flashed on the NanoVNA device to indicate battery status. This extends the frequency scanning to 1500Mhz although it may not be fully usable without a hardware upgrade. It contains experimental TDR function at this time originally released by edy555 on Github for NanoVNA the firmware release version is 0.2.2 inside the releases folder the files are provided as hex and bin need to be converted in DFU before you can use it in DfuSEdemo software unless you have a programmer for STM32 micro controller. I have converted the hex file to DFU and you may use it to flashed your device. If you don’t know what you are doing do it at your own risk the software is provided as is.

Download the files here. The original version of the files can be downloaded here

Two steps to enable battery indicator

Step 1:

Add a missing diode on the board of NanoVNA. The diode is near the battery terminal marked ad D2 this was missing on NanoVNA board you need to add one. This was use to enable the actual status of the battery if it is fully charge or empty.

Use a suitable diode for this to mount on the NanoVNA pcb, edy555 recommends 1N4148WS or B5817WS or any small diode however I don’t have those ready so I looked into my tool box (junk box) and found PG05FSESC a TVS diode for ESD protection in portable electronics. Download PG05FSESC datasheet here.

PG05FSESC diode a TVS single line diode for ESD protection marked as 5S

Test the polarity and solder the diode on the board.

Soldering the diode on the NanoVNA board

Step 2:

Flashed the DFU firmware above to your NanoVNA device I have not include the actual flashing of the firmware here, but you may watch the instructions on how to do it from my youtube channel from this link:

When flashing the file you must first use the DMR-CLEAR_MEMORY_DFU.dfu file included from the downlink above before you flash the 0.2.2.dfu file.

After flashing the firmware you just need to re-calibrate your device and it’s ready again for normal use.

Video instructions and testing of the NanoVNA after the procedure

6 replies on “Enabling battery status indicator on NanoVNA”


Do you need to restart the VNA after applying DMR-CLEAR_MEMORY_DFU.dfu ? And with or without the BOOT0 strap ? Can you describe the detailed procedure please ?

Thanks and rgds

Tnx for your reply.

Regarding the diode, I guess the Anode is soldered on the pad near the battery wire, and the Cathode (usually marked with a white bar in SMD) is soldered on the other pad, right ?

Thank you for sharing this info!
I didn’t have an SMT diode so I used an axial 1N4148 and it works fine.
To use an axial diode you have to bend the leads 180 degrees into a C shape, as small as possible radius, with fine point tweezers, then clip them off so there’s about 2mm between the ends.
It should also be mentioned that unless you un-solder 1 battery lead you will be working “hot” so be careful to not short anything while positioning and soldering.
73, –KV5R

Leave a Reply

Your email address will not be published. Required fields are marked *

This site uses Akismet to reduce spam. Learn how your comment data is processed.


Register | Lost your password?
%d bloggers like this: