I often recommend people to keep their UPS's loaded no more than 50%. However, a quick check of the left hand side LED bank can be confusing in determining your load.
Instead of being logical and making each light 20%, APC has a special formula. This tends to distort their actual load.
So a quick review...
1 bar is 17-32%
2 bars is 33-50%
3 bars is 51-66%
4 bars is 67-84%
5 bars is 85-100%
All flashing is overloaded
