2. The Scenario The Survivors: Tom Gardiner Will Hector Jake Hodges Type of Zombie: I Am Legend Statistics Duration of apocalypse: 14 days Speed: Fast (8-10 mph) Quantity: Low (4-5 Zombies per street) Intelligence: High Weakness: Sunlight
15. Power Calculations Warning, This contains loads of assumptions and I probably did some maths wrong but I threw it in anyway for a laugh (It was late). Assuming that say 300 cars in the car park, each with a 12v Lead-Acid battery, and let’s say they have an average of 50Ah and are fully charged. That’s 15kAh at 12v so 180kWh which over two weeks is only 12.8kWh, this isn’t much but assume night is 8hrs then that means we can draw 1.6kW for 8 hours, for 14 days. (We could use an inverter if found or just link 20 in series :D) A typical florescent for a sun bed is 100W, so simple that means we can run only 16 which isn’t much. However we also have the ability to charge the batteries from the cars engines. Now I’m going to assume that if we can’t hotwire a particular car then the fuel can be drained into one we can successfully.
16. More Power Calculations So apparently the efficiency of charging a Lead Acid Battery is 80% (Google); and due to voltage drop the battery will need to be re-charged when it is 10% charged. The total charge for a 50Ah battery is 2.16MJ, so that’s 1.9MJ to be charged, /.8 (For efficiency) is 2.4MJ. So a car engine is only about 20% efficient but the amount actually charging the battery is probably about say 5% (Worst case scenario). So that means we need 48.8MJ or energy from the petrol; now Petrol contains about 35 MJ/L thus assuming on average the tank has 20L in it we can charge the battery 14 times. However this is high speculative and makes lots of assumptions but we should at least be able to charge the batteries a few times…
