If a cell hits 3.65v on a unbalanced bank, the BMS disconnects completely aka potential DC Ripple.
With charge/discharge being separate, it won’t disconnect i.e. will still allow discharging, which is what one wants.
BUT, I have NO idea what will transpire on the DC bus if the BMS stops the charging dead, with the MPPT still happily providing what is asked of it.
EDIT: As I’ve said elsewhere, from what I’ve done to date, dropping the charge current manually, using the Delta, is much more controlled, for the entire DC bus side.
It is only an issue if your charger does not know about it (i.e. it is not linked to the BMS and notified). Then yes the BMS will protect itself as TTT explain and if the charger still don’t listen it will disconnect the charge.
If your system is connected then this is not an issue.
But by having two batteries in parralel you should eliminate this problem. The BMS will then balance the cells and reconnect. But if you look at the levels commercial batteries are using for their charging limits then this should not happen…
The MPPT will charge up to the voltage it was told and stop. Since this will happen very quickly (it is only charging a bunch of electrolytic capacitors) you could say the MPPT will simply stop.
Of course there is a slight upwards voltage spike as it happens, and Microcare MPPTs were once known to blow up under such circumstances, but none of the other blue stuff suffers any bad consequences.
Yes. Which is why it is better to buy two smaller Pylontech units instead of one large one (as an example). A high cell in one module (aka string) causing that module to disconnect still leaves the rest of the battery fully operational.