Using information in the chart of energy values on this page, estimate how many fully charged car batteries are needed to store the same amount of energy as one litre of petrol.
According to the chart, one litre of petrol contains approximately 34 megajoules of energy. The energy capacity of car batteries can vary, but a typical fully charged battery has an energy capacity of around 13 kilowatt-hours (kWh), which is equivalent to 46.8 megajoules (1 kWh = 3.6 megajoules).
Therefore, to store the same amount of energy as one litre of petrol, it would take approximately 1.45 fully charged car batteries (34 MJ ÷ 46.8 MJ/battery = 0.725 batteries; rounded up to the nearest whole number, this is 1.45 batteries).