It would be useful if the alternator field data being fed back to the Cerbo GX could be used to determine if an error or warning should be raised when taking a BMS offline, as the alternator can suffer catastrophic damage when large high output alternators are outputting power and the BMS is put into Standby or Off from the display.
This is a well known issue with Lithium banks that have high acceptance rates, and while we were well aware of the problem of doing this, inadvertently bumping the off setting while confirming settings on the BMS just cost us a $2000+ alternator, and express shipping to a foreign country for the replacement.
While it was surely my mistake, reviewing setting s as we diagnosed a low charge output in heavy seas complicated the issue, as I hit the touch screen to standby as a wave boarded us on the beam inadvertently, instead of backing out to the previous menu as I intended.
A confirmation dialogue would have saved us.
Further safeguards when the field strength is high enough to potentially damage the alternator would be even better.
Since this issue is so cut and dried, it feels like this could be a safety feature you build into the Cerbo GX firmware.
Victron Lynx BMS is controlled from the Cerbo GX touchscreen. In an all integrated Victron system using Lynx BMS, Lynx Distributors, Multiplus II charger/inverter, Victron LiFePO4 Smart Batteries, Wakespeed Alternator Regulator, etc. all can be controlled from the Cerbo Touchscreen. Very common in large yacht installs as external BMS is a requirement under ABYC, and many insurers require ABYC TE-13 certified installs, especially on yachts valued at over $1m (which is pretty common these days).
I am running a similar system but with NG batteries and Lynx NG and WS500 so I have just had a look because I was wondering what menu you had found. I thought it was just an indication that the BMS was on, but have now found if you click you get the option to set it to standby. I know Victron are adding confirmation to some menus like shutting the inverter down from VRM or the Cerbo. Hopefully this one will get updated.
The one thing with the Lynx BMS to WS500 is the recommendation to connect the WS500 feature in wire / ignition to the alarm relay (I have done this) and added a Balmer alternator protection module (I know these are not 100% effective).
Questions are
Did you have the WS500 feature in / ignition wire running through the alarm relay with the setting for the alarm relay as “alternator” in the Lynx BMS to get the 2 seconds advance shutdown of the alternator before the contactor opened.
If so then the question for Victron (which I will raise) is does the 2 second advance opening of the alarm relay also apply when the state of the BMS is changed (for whatever reason) from on to standby or off.