SAN FRANCISCO — Lawyers for a proposed class of Apple Inc. consumers sued the company this week, claiming customers were misled about the storage capacity of their iPhones, iPads and iPods.

Plaintiffs lawyers contend Apple didn’t inform customers its iOS 8 operating system uses between 18 and 23 percent of a devices’ storage capacity, leaving users with less space than advertised. The lawyers say Apple compounds that harm by aggressively marketing its iCloud storage system. When users run out of space, according to the complaint, ads pop up offering iCloud storage for up to $29.99 a month.