Automotive Relay style CJ7320 / CJ730 / LK720 Not displaying vehicle battery voltage

benjamingraya month ago

Hello fellow Traccar enthusiasts.

I have installed a traccar instance on AWS lightsail using the very helpful guide from youtuber "Pitloon Garage" (https://www.youtube.com/watch?v=476E1ioFSVg).

I have an automotive relay style tracker (aliexpress special) which appears to be sold under various names including CJ720, CJ730, LK720.
I have configured it and it is now track-able on my traccar web interface and android "Traccar Manager" app which I am very pleased about.

My problem is that I cannot see the display of the vehicle voltage (12v motorcycle). Before I heard about Traccar I was using the chinese gpscj.com server and the "Yi Tracker" android app, both of which were functional and would display vehicle battery voltage in the platform (i.e 11.8, 12.4v etc). However I cannot see this in the Traccar interface.

I know that the tracker I have has a very small internal lipo cell per Voltlog's excellent series of videos on the product (https://www.youtube.com/watch?v=gPs1qvC4kUo). I can see a battery level in the Traccar interface which translates the h02 protocol message into the following levels:

6=100% 5=80% 4=60% 3=20% 2=10%

I believe the battery level shown in traccar is that of the internal cell since it never deviates from 100% which you would expect given it's being constantly topped up by a much larger capacity 12v battery.

I know that it is possible to get the 12v battery voltage from the tracker because it was shown in the chinese server interfaces so I am hoping it will also be possible using traccar as it is rather useful !

benjamingraya month ago

when i click on the green button with 3 dots on the device popup and then click more details, there are the following:

Status 4294965759
io1 234
io2 15

I dont know what any of these parameters represent, i'm wondering if perhaps one of them could be decoded into a vehicle battery voltage perhaps? Any help in understanding these would be greatly appreciated

benjamingraya month ago

Furthermore, I have been inspecting the h02 protocol documentation.
In one of the resources https://www.traccar.org/protocol/5013-h02/ICARGPSProtocol.xlsx it provides an example protocol message.

As far as I can tell there are a few different types of messages between the client and the server (having looked at the traccar logs)

  1. Messages from the tracker to the server:
2024-10-16 22:19:15  INFO: [T8f0300b2: h02 < 148.252.146.21] *HQ,IMEIXXXX,V1,221728,V,LAT,N,LONG,W,000.00,000,161024,FFFFF9FF,234,15,0,0,6# 
  1. Confirmatory responses from the server to the tracker
2024-10-16 22:19:15  INFO: [T8f0300b2: h02 > 148.252.146.21] *HQ,7201042441,V4,V1,20241016221915#
  1. Messages that i dont quite understand, but having read the h02 protocol documentation it seems to be analogous to the first 1. messages?
2024-10-16 22:24:28  INFO: [T8f0300b2: h02 < 148.252.146.21] 24720104244122242616102451332685060000841126000000fffff9ffff001d2a0000000000ea0f00000000007e0e

Regardless, comparing this 3rd message type to the exemplar in the .xlsx spreadsheet protocol reference document I linked to above (will attach screenshot also) it suggests that the penultimate parameter of this message relates to 12v battery voltage

suggestions welcome!

Screenshot 2024-10-16 at 11.44.16 PM.png

Anton Tananaeva month ago

There's a good chance it's not supported because there are many variations of H02-based protocols.