Victron 12.8 Volt Lithium Ion Phosphate Batteries

Lithium-iron-phosphate (LiFePO4 or LFP) is the safest of the mainstream li-ion battery types. The nominal
voltage of a LFP cell is 3,2V (lead-acid: 2V/cell). A 12,8V LFP battery therefore consists of 4 cells connected in
series; and a 25,6V battery consists of 8 cells connected in series.

In several applications (especially off-grid solar and/or wind), energy efficiency can be of crucial importance.
The round trip energy efficiency (discharge from 100% to 0% and back to 100% charged) of the average lead acid battery is 80%.

  • The round trip energy efficiency of a LFP battery is 92%.
  • The charge process of lead-acid batteries becomes particularly inefficient when the 80% state of charge has
    been reached, resulting in efficiencies of 50% or even less in solar systems where several days of reserve energy
    is required (battery operating in 70% to 100% charged state).
  • In contrast, a LFP battery will still achieve 90% efficiency under shallow discharge conditions.