According to a 2003 report entitled "Getting the Lead Out", by Environmental Defense and the Ecology Center of Ann Arbor, Michigan, the batteries of vehicles on the road contained an estimated 2,600,000 metric tons (2,600,000 long tons; 2,900,000 short tons) of lead. Some lead compounds are extremely toxic.
This comes to 167 watt-hours per kilogram of reactants, but in practice, a lead–acid cell gives only 30–40 watt-hours per kilogram of battery, due to the mass of the water and other constituent parts. In the fully-charged state, the negative plate consists of lead, and the positive plate is lead dioxide.
In 1992 about 3 million tons of lead were used in the manufacture of batteries. Wet cell stand-by (stationary) batteries designed for deep discharge are commonly used in large backup power supplies for telephone and computer centres, grid energy storage, and off-grid household electric power systems.
Conventional vehicles typically rely on Lead Acid Car Battery due to their high power output and affordability. These batteries use water-based electrolytes and have individual cell voltages that are relatively low. While they offer proven safety, lead-acid batteries have a lower specific energy compared to lithium-ion types.
While they offer proven safety, lead-acid batteries have a lower specific energy compared to lithium-ion types. In contrast, hybrid electric vehicles often use nickel-metal hydride (NiMH) batteries because of their long lifespan and ability to undergo many charge/discharge cycles. What is a lead acid car battery?
Typical parameters for a Lead Acid Car Battery include a specific energy range of 33–42 Wh/kg and an energy density of 60–110 Wh/L. The specific power of these batteries is around 180 W/kg, and their charge/discharge efficiency varies from 50% to 95%.