This paper is devoted to the effect of FORAFAC 1033D (polyfluoroalkyl sulfonic acid) as electrolyte additive on the performance of standby VRLA AGM batteries. This additive has a surfactant character and its stability is increased by substitution of some hydrogen atoms by fluoride atoms in the molecule. With the use of FORAFAC, the objective is to improve the life of VRLA lead acid batteries for standby applications. Comparative accelerated floating tests with and without FORAFAC have been carried out on standard AGM batteries. Batteries containing FORAFAC in acid at low concentration (0.1%) show a remarkable electrical behaviour during the test. A good influence of FORAFAC on water consumption and on self-discharge is also observed. Results indicate that the life duration of standby VRLA lead acid batteries could be improved by a factor 1.5 to 2 with the use of FORAFAC. The mechanism of the FORAFBC action has been investigated and is discussed in this paper. The use of the FORAFAC method appears to be a very promising solution in order to improve the behaviour of batteries for standby applications. For example, it could be useful for applications at higher temperatures or to increase the specific energy of batteries by the utilisation of thinner grid collectors and plates.