There is a recent market trend towards industrial battery powered products that demand occasionally very high discharge rates. This fact is today solved by oversizing the battery or by using more expensive high power nickel-cadmium batteries. Within an EC funded project, ultra high power lead-acid batteries for UPS applications are being developed. The batteries are characterised by a thin electrode design linked to the use of novel separator materials to increase the battery life under floating and deep cycling conditions. Battery performance under different working conditions is presented, in comparison to standard products, and the battery improvements and failure mechanisms are also discussed.

Nickel metal hydride (Ni/MH) is presently the most promising battery system for electric and hybrid vehicle propulsion in the short and mid-term. This paper presents the results obtained in the development of prismatic Ni/MH batteries for high power, mainly hybrid vehicle, applications.Valve regulated Ni/MH cells rated at 25 and 60 Ah have been designed and assembled using improved positive and negative electrodes. Both types of cells showed excellent high rate discharge capability and fast rechargeability and a satisfactory charge retention when stored and cycle lift, under deep cycling and hybrid vehicle working conditions. On the other hand, energy and power efficiency ratios were improved in the 60 Ah cells. (C) 2001 Elsevier Science B.V. All rights reserved.