Behaviour of Systems Mixing Parallel Strings of Lithium-Ion and Lead-Acid Batteries for Telecommunications Applications

Lithium-ion batteries offer many attributes that are attractive for telecom reserve applications relative to flooded and VRLA technologies. These attributes include much higher energy density per unit weight and per unit volume, no hydrogen outgassing, no thermal runaway mechanism, and much lower steady-stage float current. Lithium-ion batteries are particularly attractive for sites where floor space or floor loading is a limiting factor for expansion of existing lead-acid sites. System level understanding and management of mixed-mode reserve systems with parallel strings of lithium-ion and lead-acid batteries is critical for successful deployment at these sites. This paper discusses system behaviour when mixing parallel strings of lithium-ion batteries with lead-acid batteries for capacity expansion of existing lead-acid sites