Batteries.

The battery is on of the most important components of the car with out the battery the car cannot function. The battery voltage when the battery is fully charged is 12.6V but when the battery is only half charged it is at 12.4V. The minimum voltage a battery could be at while under load (having one of the accessories on, headlights etc.) is 9.5V. One of the main hazards when around a battery is it could explode in your face and cause serious injury, batteries realise the flammable gas called hydrogen and if the fumes come in contact with a naked flame then it will explode. Inside the battery there are 6 things called ‘cells’ and they are in a parallel line, each cell when the battery is fully charged produces 2.1V. If the car doesn’t crank/start then there is only two things it could be, power and fuel. The first thing to check is that if the car is getting power so you start at the battery, the most important thing is that there is a battery in the engine bay!! Then you can move on to checking the voltage etc. if the battery has been on charge and is now over charged (12.75V) then you can remove the surface charge buy putting it under load for approx. 2 minutes then you can check the available voltage with a multimeter and keep putting it under load until it reached 12.6 VOLTS

 

Above is the inside of a better and the 6 cells that produce 2.1 volts each.