R.H. NEWNHAM, ADVANTAGES AND DISADVANTAGES OF VALVE-REGULATED, LEAD/ACID BATTERIES, JOURNAL OF POWER SOURCES, 52, 149-153, 1994

Abstract: To improve the standard of living in many parts of the world, an efficient energy-storage medium with low-maintenance requirements is essential. Valve-regulated lead/acid batteries (VRBs) have the potentials to offer such a service at a competitive cost. Since there have been a few critical analyses of the efficacy of this technology, this discussion examines the advantages and disadvantages of using URBs in energy-storage applications. VRBs possess the following advantages: no water maintenance; little chance of acid spillage; negligible emission of acid and hydrogen; no special ventilation needs; minimal overcharge required at normal temperatures; easy to transport, and can be operated on their side. In addition, the gelled-electrolyte design of VRB is resistant to acid stratification, while the adsorptive glass-microfiber type has an excellent high-rate discharge performance. On the other hand, VRBs are not as resistant to overcharge as flooded-electrolyte units and must be charged very carefully to reach an acceptable service life. Other disadvantages include: specific gravity cannot be measured; a limited shelf life of two years, and an increased likelihood of thermal runaway.