My 2019 (from former boat owner) purchased 2 x 200 Ah LifePo4 Victron batteries have a significant reduced capacity. Bulk-Charging from landline via Philippi charger and solar bulk charging take forever. The maximum capacity is terminated at 280 Ah in sum of both batteries. The B2B system to an AGM is working fine. The alternator charger (Sterling) from the vessel's diesel to the starter is fine as well.
How can I locate the problem within the batteries? If there is a problem, who can be contacted at Victron, since the batteries worked perfectly the last 2 seasons...