Question : Problem: Power Backup lights status meaning

What does it mean when the lights on the right hand side (battery symbol beside them) of the unit flashes green?

Answer : Problem: Power Backup lights status meaning

If it is this model:

http://www.apc.com/resource/include/techspec_index.cfm?base_sku=SU1400RM

It means that there is an internal failure of some type and you should not use the UPS system.