more life

English as a Second Language English Vocabulary, Grammar and Idioms
1
  1. CFLs(compact fluorescent lamps) with electronic ballasts are more common and have more life span.
  2. CFLs(compact fluorescent lamps) with electronic ballasts are more common and have more life.
    Please correct the above.
    Thanks.
2

Both are possible.

3
  1. CFLs(compact fluorescent lamps) with electronic ballasts are more common and have a greater life span.
  2. CFLs(compact fluorescent lamps) with electronic ballasts are more common and have a longer life.

‘More life’ is distinctly odd in the context of electric components.