Switch to disconnect battery and SCC

[sunrise]

Hi all,
In my to be built system (200-300w panels + Victron SCC + 200ah Lithium battery + JBD BMS) I plan to have a disconnect switch for the battery. With that in the off season (long, wet winter in PNW) I can disconnect the battery and leave the battery in storage mode. This switch also allow quick disconnect the entire 12v system in the trailer should anything go wrong.
Also even without this switch, from time to time I will need to take out the battery and access the space beneath the battery.
But after reading some posts seems like it's a bad idea to have battery disconnected while having SCC still connected to solar panels, seems like there are design using BMS controlled relay. But I have not found the schematics include this design from any of Will's blueprints, any link to this design would be much appreciated.
Of course I could always add another switch to disconnect SCC from panels, but for that I'd have to remember to disconnect things in correct order and I'd rather have a simpler way to handle this.

Thanks,

 

[Craig]

It has been decided that switching off the batteries while having the panels on is not the end of the world. No one has been able to point to a case where a SCC was ruined. My recommendation for simplicity sake is to add the switch to the panels. I think this should be done no matter what just so panels can be turned off easily if youneed to work on SCC or something like that.

I am alos afraid a BMS based system could drain your batteries while away as they will draw some current even when left at idle.

 

[CascadeOffGrid]

In my experience, SCCs are only damaged when removing the battery connection while the system is charging at a high power level. You should always disconnect the panels first and then disconnect the SCC if you are actively charging at higher amperages. If the sun isn't high in the sky, I wouldn't worry about it too much.

 

[RickP]

I have a breaker on the incoming PV positive leg, and (of course) one on the battery positive. This takes care of any disconnection needs. Victron has stated pretty definitively that their SCCs will not be damaged, even if repeatedly disconnected from the battery under load. But it never hurts to put in an extra level to avoid stresses, even if they aren’t fatal in nature.

For what it‘s worth in your considerations, Will has been so far unable to burn up an SCC, even a cheap one, by disconnecting it from the battery bank. There’s a post about it on the forums.