A divided San Antonio City Council voted 8-3 Thursday to authorize a 4.25% rate increase that CPS Energy officials said is necessary to help replace aging equipment, keep up with rapid customer growth and transition to cleaner energy. However, that approval only came after a 5-6 defeat of an amendment that would have shrunk the size of the proposed hike by half. It also followed concerns raised by multiple council members that the city-owned utility hasn’t done enough to shield financially vulnerable residents from rate increases, however necessary they might be.