Here is the link to the manual: https://learn.fortresspower.com/external/manual/eflex-5-4-manual?p=dc8b9a9c1b3f410556835193e66f22573ff1dced9b225dfe0940054a527a3680
Battery Charge Level Storage for 48 Volt Batteries Here’s what Fortress Power typically recommends for storage: Partial Charge for Storage: Store the battery at 40% to 60% state of charge (SOC) if it will not be in use for a few weeks or longer. ...
The Fortress eFlex 5.4 has been successfully evaulated per UL9540a unit test procedures. Please find the test report here: UL9540a Large Scale Fire Test Report