Victron energy BMV-700 Anleitung Seite 35

If the midpoint alarm trips much earlier (and does not trip during
charging), some batteries or cells may have lost capacity or may have
developed a higher internal resistance than others. The battery bank may
have reached the end of service life, or one of more cells or batteries
have developed a fault:
a) In case of series-parallel connection, disconnect the midpoint parallel
connection wiring and measure the individual midpoint voltages
during discharging to isolate faulty batteries or cells.
b) Charge and then test all batteries or cells individually.
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