The national electricity companies of Cameroon and the countries of the sub-region have difficulties to meet the demand. This imbalance between demand and production results in power cuts, commonly known as "load shedding". To cope with these cuts, our backup systems are positioned as an alternative or an addition to generators: for those who live in an apartment or whose access to their office / store / practice does not allow the use of a group; for those whose equipment is critical and can not withstand the defects of the sector (eg medical or computer equipment); for those who do not want to manage the stress of maintaining a group or its fuel supply whose prices remain volatile. These systems consist of a converter-charger and a set of stationary batteries: they are silent, maintenance-free, and above all without fuel. Their principle of operation is simple: when the sector is present, it allows to recharge the batteries. At the moment of a power failure, the system switches automatically and instantly to the batteries. When returning from the mains, the system then recharges the batteries for the next break.