Lynx bms OFF to ON

[Vuser1]

I was reading the manual of lynx bms (7. Commissioning and Operation of the Lynx Smart BMS) and it mentions the transition from off mode to on mode:

If the Lynx Smart BMS was off due to low cell voltage or low SoC shutdown, it will exit OFF mode and return to ON mode when

• it detects a charging voltage >11.7V (>23.4V for a 24V system or >46.8V for a 48V system) than the battery voltage on the system side or

Am I reading it correct that if I have a 12v battery, the charging voltage needs to be at least 12 + 11.7 =23.7 v to “wake up” the bms?

In addition, a fairly recent (2022) post by victron staff (Lynx Smart BMS still needs Battery protect? - VictronEnergy) said the lynx bms contactor won’t automatically reconnect:

In addition, a BatteryProtect switches off at a voltage to be defined and switches on again at another voltage. The Lynx Smart BMS does not do this

Did anything change after that post?

[pwfarnell]

There is a typo in that sentence, you obviously do not need a 24V charger to wake up a 12V battery, that would be plain dangerous. It probably means that the charger voltage has to be at least 11.7V AND above the battery voltage. I will raise it with Victron.

In terms of the contactor, then yes it does automatically close when it detects the presence of a charging voltage as discussed in your first question.

The point about the Battery Protect is that you can set it to disconnect loads at voltages of your choice, so it opens prior to the contactor, disconnecting optional loads.