Attempt to start car – If it doesn’t start and you determine it’s the battery, make sure anything that can drain the battery is turned off (e.g. radio, windscreen wipers, etc.). Don’t attempt to start it too much as this will drain the battery further.
Find your jump cables – If you don’t have jump cables or a jump starter this could prove to be difficult and you may need to call a recovery service.
Call a friend or find a ‘good Samaritan’ (booster car) – You will need another car with the same or similar voltage (most cars are similar). Parked front ends together but not touching.
Turn off the booster car – To attach jump cables, turn off the booster car’s power.
Attach Positive end of the jump lead to booster car battery and then the other positive end to the flat car battery. Important positive (+) to positive (+)!
Attach negative jump lead to negative port on booster car and then an earth point on flat car. Connecting to earth point can be any metal object that earths the car. This can be an object off of the car, for example a sign post. You can connect to the negative point on the flat battery however this may cause sparking and even cause the battery gasses to combust so isn’t advised.
Once clear, start booster car and leave to run for a few minutes – Start the booster car as soon as possible as to not drain the booster cars battery too much.
Start giving the booster car acceleration in neutral – Giving the car gas will cause more electricity to pass through the cables to the flat battery.
Turn the key on the flat car whilst accelerating in neutral – If it starts then great! If it doesn’t, leave it a few more minutes and try again. Once you have been trying for a while with no luck disconnect the jump cables as you don’t want to leave two cars stranded. This may mean you need a new battery or to charge this one up.
If your car has started make sure you disconnect the wires in the same order you connected them in – Do not turn off the flat car until you are either at a garage or at a location that it does not matter if the car doesn’t start. A minimum of 15 minutes driving time at 40mph is advised, however, if you are in a location where the speed limit doesn’t allow that be weary that the car may not gain sufficient charge. Having a completely flat battery can cause it to not take any charge again.