If you’ve been driving for a long time, chances are you’ve experienced a flat or dead battery.
You know the symptoms. You unlock your vehicle, get inside, but when you turn the key or push the button, nothing happens.
Sometimes, this is the case even if your dashboard lights up. Other times, the battery is so flat (or dead) that you can’t even electronically unlock your vehicle.
Naturally, the first solution to a flat battery is to get a jump start. If you have one of those power banks for juicing up a battery, that’s a great solution, too.
But what if you neither have jumper cables nor a power bank?
If your car has a manual gearbox, you could ask for help to push-start your car.
PUSH-START YOUR CAR
You’ll need a couple of strong folks to do the pushing. They’ll have to roll your car out of the parking space and position it so you have a fairly long straight ahead of you.
Turn the key or press the ignition button so that it’s in the “On” position. Next, shift into second or third gear and keep the clutch pedal depressed.
When the path ahead is clear, ask the good Samaritans to push-start your car. When your vehicle is going at a jogging pace, drop the clutch pedal – do not release it slowly!
The sudden release of the clutch should be enough to get the car started. If it does not work, ask your friends if they can try again.
WHEN YOU CAN’T PUSH START YOUR CAR
Unfortunately, you cannot push-start your car if it has an automatic gearbox. This applies to dual-clutch transmissions as well.
This is because the manual friction clutch provides a positive coupling between the driven wheels and engine.
But this is not the case with an automatic transmission, which has a fluid coupling. Also, with most automatic transmissions, you need the engine to be turning first before “Drive” can be hydraulically engaged.
The dual-clutch gearbox uses a friction plate clutch arrangement, and the selection for drive is controlled by a mechatronic system. It needs both electrical and hydraulic pressure in order to operate.
Electrical energy is supplied by the alternator, while hydraulic pressure comes from an engine-driven pump. Therefore, until the engine is started and stays on, the dual-clutch gearbox will not function.
In such a case, the only way to start the engine is to jump-start it using another battery.
As mentioned earlier, you can also purchase compact lithium-ion power banks designed to provide the voltage to start a car with a flat battery.
Here’s how to jump-start your car!
Mechatronics: How does it work?
We explain how a dual-clutch gearbox functions