SAO PAULO, Sept 24 (Reuters) - Consumer confidence in Brazil reached a 5-month low in September, as higher inflation, potential problems in electricity supplies and political uncertainty contributed to pessimism. Brazil’s consumer confidence index for September released on Friday by FGV fell 6.5 points to 75.3, the lowest since April. Viviane Bittencourt, responsible for the index at FGV, said confidence has been eroded for multiple reasons, including high inflation and unemployment and political uncertainty. Although all consumers are pessimistic, those with lower incomes have a more negative outlook on the economy.