Lithium batteries

In recent years, photovoltaic systems for self-consumption applications are using more and more lithium batteries (NMC, Liife PO4, LMO ...). The reasons are numerous: the volume has created a significant drop in prices, its lifespan is high and the yield is significantly higher than the performance of lead batteries. But also they are lighter, less bulky and have a better energy density.

The life of lithium batteries varies between 3,000 and 6,000 cycles at 80% DOD depending on the manufacturer. In the case of a self-consumption system, the optimal operation must be one cycle for one day of operation. The charge is made by the surplus of electricity generated during the day and the discharge by the consumption of the evening and the night. Thus, a lithium battery will have a lifetime between 8 and 16 years. These lifetimes announced by the manufacturers are to be modulated because they result from tests carried out under standard conditions that is to say without high temperature and without high charge and discharge currents which have a negative impact.