I urge Victron to either change the procedure for recovering from a BMS OFF mode. Or limit the path into the OFF mode.
I entered the OFF mode through the VictronConnect app in a marine off-grid installation. I usually select standby, this time I selected OFF. This turned out to be an almost irreversible system-suicide. There is no good path to turn the BMS on again. Note, the batteries were full ! Access to the Cerbo didn’t help, because the Cerbo had no life-signal from the BMS.
Fortunately, my phone had access to the internet, which is not always the case for off-grid settings! After considerable effort in reading the manual “troubleshooting and support”, I found myself beneath the floorboards fiddling around with a tiny BMS-wire, which I had to unscrew and reattach after 5 seconds. If I had not had access to the internet (mobile phone) to read this chapter, I would have been left with full batteries and no navigation, anchor windlass, radar, VHF. The reason why I bought Victron components is to have reliable access to navigation, radar, VHF …
There is no way, a typical customer will know the content of chapter 7 “troubleshooting and support” by heart, thus knowing how to recover from an OFF mode. Boaters will likely have the BMS-Bluetooth turned off, to save energy or certainly to eliminate the (disturbing) blinking BMS-bluetooth LED. I urgently suggest to enable a more intuitive and practical pathway through the Cerbo to recover from the BMS-suicide.
No BMS-Bluetooth is always off - I didn’t see a need for the BMS-Bluetooth, because the Cerbo offers all connectivity I need. I used the VictronConnect App to turn the BMS OFF.
I think I understand.
You used remote VictronConnect?
But it wasn’t really clever.
How did you think you would turn it back on if everything is off?
The Bluetooth needs almost no energy.
According to the datasheet the BMS needs 0,3mA in OFF mode (I’m pretty sure that’s with BT) at 12V that’s 0,007W.
Well. Now, in hindsight it is entirely clear to me that it is not the Victron-intended procedure. In your words “not really clever”. My point is: it is a trap anyone can easily step into. It is a nasty trap if people are in remote places (boats or campers), with no good way to recover.
I have NG batteries for my boat and there is no way I would ever turn off the BMS Bluetooth, it is your only access when off. It uses at most 1Ah per month so not an issue. I keep copies of all manuals on my tablet, this is important learning for boating where mobile internet can not be guaranteed. Finally, I assume you had to disconnect the remote wire, why did you not connect the remote terminal to an accessible switch in your electrical panel. Such a switch is specified in boat install standards for lithium, both ISO and ABYC.
If the battery + bms are in a hard to reach place then the remote on/off would better set up for you if you intend to switch it off. (Since the BT is off)
I wrote my post not because I am concerned about re-executing the same mistake. I am convinced that others too will walk into the same trap. But your point (and also of pwfarnell) is super-valid: yes a remote on/off switch will add practical maneuverability and safety.