This was a recently recommended battery by the solar nerds: https://www.enersour.com/Wall-Mounted-Battery-E3-51-2V-300Ah-314Ah-pd775302098.html
cell certifications: CE, UL, IEC 62109-1&-2, IEC 62477, EN61000, UN38.3
battery certifications: CE, UN38.3, MSDS, DG
The 16.077 kWh version...