Our boat, built 2017, has 2 Victron battery boxes, each with 4x90Ah Lifepo4 batteries installed (in total 8x90Ah batteries). Color Control shows 166 total charge cycles. The system worked fine for 5 years. The batteries predate the Smart batteries - meaning no Bluetooth connection.
All batteries in one box deteriorated in the past weeks or months and two batteries failed entirely with low voltage and don’t take a charge anymore. One battery seems okay but triggers a high voltage alarm. All the problematic batteries are in one box. The other box works fine.
What could be the reason?