Glossary of Terms Used to Specify Battery Performance Parameters

2 Glossary of Terms Used to Specify Battery Performance Parameters 

This section defines glossary terms used to specify battery performance parameters. Prospective battery designers who want to be involved in the design and development of next-generation batteries for electric vehicles (EVs) and hybrid electric vehicles (HEVs) should become familiar with these terms. 

Cycle life Cycle Ufe is the most critical performance parameter and is defined as the number of cycles delivered by a rechargeable or secondary battery before the battery s rated capacity falls to 80% of the initial capacity in a particular application. 

Power density. The power delivered by a battery expressed in watts per bter. Rated capacity. The nominal capacity dehvered by a battery as a specific rate of discharge in secondary cells and rated at a C/10 current and at C/100 in the case of primary cells. This is particularly used to calculate the energy density. Specific energy. The nominal energy of a battery expressed in watt-hours per kilogram. 

Self-discharge-. The loss of capacity of a rechargeable or secondary battery expressed in percent of the rated capacity lost per month at a given temperature. 

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