# Can an incorrect CANBus cable drain the battery? **URL:** \ **Category:** Q&A and troubleshooting\ **Tags:** multiplus\_vebus, offgrid, diy\ **Created:** [27 November 2024 16:35 UTC](https://community.victronenergy.com/t/can-an-incorrect-canbus-cable-drain-the-battery/13409 "2024-11-27T16:35:54Z")\ **Posts on this page:** 5\ **Page:** 1
**Author:** ![houser](https://avatars.discourse-cdn.com/v4/letter/h/4da419/32.png) [@houser](https://community.victronenergy.com/u/houser)\ **Post date:** [27 November 2024 16:35 UTC](https://community.victronenergy.com/t/can-an-incorrect-canbus-cable-drain-the-battery/13409/1 "2024-11-27T16:35:54Z")
Need some preliminary advice on a rather weird incident if someone with knowledge can help? I have a friend that has run a DIY Victronsystem with a 6kWh LiFePo 48V battery offgrid and it has worked without issues for a year or so. Venus GX, CANBus BMS, Multiplus. He today called me after uploading an (incorrect?) veconfigurefile after which the battery voltage dropped pretty quickly, from 53.5 to 49V in maybe two minutes according to the logs. This could be causality/correlation I guess, but it did happen after this upload. My question: Could this be caused by an incorrect CANbus cable only? I can think of some other external things which the troubleshooting will hopefully tell but for now, since the system was working well, is this a possibility? ---
**Author:** ![houser](https://avatars.discourse-cdn.com/v4/letter/h/4da419/32.png) [@houser](https://community.victronenergy.com/u/houser)\ **Post date:** [28 November 2024 07:53 UTC](https://community.victronenergy.com/t/can-an-incorrect-canbus-cable-drain-the-battery/13409/3 "2024-11-28T07:53:31Z")
Thanks for reply, appreciated! I understand that the voltage drop can not be due to a 4kWh draw but I guess I am wondering if it could be caused by an incorrect veconfigure file that might have affected the readings in the GX via the Multiplus. Might be a long shot, but if that is not it, I guess we suspect a damaged battery or cabling via rats or water or something. No one at the site at this time that can check physically. ---
**Author:** ![lxonline](https://dub1.discourse-cdn.com/victron/user_avatar/community.victronenergy.com/lxonline/32/25567_2.png) [@lxonline](https://community.victronenergy.com/u/lxonline)\ **Post date:** [28 November 2024 11:53 UTC](https://community.victronenergy.com/t/can-an-incorrect-canbus-cable-drain-the-battery/13409/5 "2024-11-28T11:53:58Z")
The battery could have tripped on the restart with the inrush. It is usually best to these things with no loads. ---
**Author:** ![houser](https://avatars.discourse-cdn.com/v4/letter/h/4da419/32.png) [@houser](https://community.victronenergy.com/u/houser)\ **Post date:** [30 November 2024 09:57 UTC](https://community.victronenergy.com/t/can-an-incorrect-canbus-cable-drain-the-battery/13409/6 "2024-11-30T09:57:47Z")
Thanks for your replies! An engineer has been to the site and although no visible damage, the battery is not accepting a charge, the app that comes with the battery says nothing is wrong and reports 100% SOC and correct voltages but the Victron gear is displaying low voltage warnings. I suspect a faulty battery or the onboard BMS and can not see how any of the actions taken might have caused this. Not uploading the veconfigure file and not any faulty can bus cable or such could have caused this. Or am I missing something obvious? They will try a reset of the BMS and if that does not help, it is probably warranty time. ---
**Author:** ![houser](https://avatars.discourse-cdn.com/v4/letter/h/4da419/32.png) [@houser](https://community.victronenergy.com/u/houser)\ **Post date:** [30 November 2024 14:09 UTC](https://community.victronenergy.com/t/can-an-incorrect-canbus-cable-drain-the-battery/13409/7 "2024-11-30T14:09:33Z")
It was not a plain firmware file, but some veconfigure file.