No, I recall them having smartphones (or I should say sumafo).
Maybe all their supplemental mechas were trashed in the episodes leading up to the finale and they were left going back to the basics. I've seen that sort of thing happen occasionally in toku shows. Maybe the components of Maximum Kizuna Kaiser survived the destruction of the rest because they had the strongest bonds with the Five. (Then again, with a name like "Maximum," maybe they are the later mecha that supplanted the originals. Though I don't recall if we saw them in the flashbacks with early episode numbers.)