Everyone knows how to start a car with a discharged battery: "light a cigarette" from another car. How to start the engine correctly.
The storage battery is the primary energy source for the vehicle. If it is completely discharged, it is usually impossible to start the engine in the usual way. Is it possible to accelerate the car downhill and turn on the gear. You may be lucky - there is enough residual voltage to excite the generator. But it is safer, and sometimes easier to "light". Most often, the "lighter" is a charged battery of another car and its generator.
Not every wire will help out
Experienced, knowing about the ability of the battery to fail completely unexpectedly, carry with them, just in case, wires for "lighting". Let us remind those who rely on thrifty colleagues: other people's wires can be simply dangerous at work - for example, if they are without ticks, that is, "crocodiles". The starting current of the starter is measured in hundreds of amperes, so you risk getting burns if you hold such wires on the terminals with your bare hands. It happens that the wires are too thin, or they are not made of copper, but of something copper-plated (we have also seen such "branded" ones). Possessing great resistance, they will not allow the required starting current to flow. Therefore, when choosing cables, first of all, let's pay attention to the cross-section of the core: it must be at least 16 mm2. The length of the wire is 2–2.5 m, and the color of the positive and negative wires is different (usually “plus” is red). Between each other, it is advisable to tie the cables with electrical tape, and to minimize the risk of shorting the clamps, move the cables relative to each other. On store wires "crocodiles" are often made so that the area of their contact with the battery terminals is small. It is better to replace these immediately - say, with electric welding ones, as in our picture. It is desirable that the insulation of the wires is rubber: it dubs less in the cold and does not melt when it touches, for example, a hot collector.
By the way, on some foreign cars it is not allowed to cling to the battery pins. And sometimes this is simply impossible due to the peculiarities of the layout. Usually, the pictogram and instructions for the car warn about this - special terminals are provided for connecting the power wires, which can be located, for example, in the "frill" in front of the windshield. When “lighting” the car, you don't have to open the hood, and in the event of an explosion (God forbid!) The battery is much safer. By the way, on many cars the terminals themselves, put on the pins of the battery, are made elongated - here you can "light up" with convenience.
Which of the wires - "minus" or "plus" - is connected to the donor first, it does not matter, if only the ends are not closed. Nevertheless, practice shows that it is more convenient to first connect the "pluses", then put the ticks on the "minus" of the donor and, last of all, connect to the "minus" of the dead battery. The main thing is not to short-circuit the cables by accidentally touching the "ground" with the wrong wire. Well, when connecting the last "crocodile" to a discharged battery, do not be afraid of the spark! It is natural, because at the first moment a current of about 50 A will flow into the empty battery.
Do not turn on the starter, barely connecting the wires. To reduce the discharging of the donor's battery, we start up its engine in advance and maintain an average speed. In the first minutes after connection, the discharged battery is intensively charged; at the same time, contrary to rumors, there are no fatal effects on the wiring and ECU of the donor car, just a weighty additional load has appeared in its network. But when we turn on the starter, the starting current will be given immediately by two batteries connected in parallel!
Let's say the engine starts successfully. Let it work for three to four minutes, it will warm up, the battery will recharge, and after that we will disconnect the wires. Otherwise, the car may stall - and you will have to start all over again.
We first disconnect the wires from the donor - its battery is well charged, and if the clamps removed from another battery accidentally close, the pop and flash will be impressive: thin wires of other systems - alarms, radio, etc., can burn at the donor's terminals.
If we light up from a small auxiliary battery, of which there are many on sale, then there is no point in holding a pause for preliminary recharging of the reanimated battery - the capacity of the assistant is small, its voltage may drop dramatically, and it will hardly rise in the case of a dead battery. As a result, we get two weak batteries that will not be able to crank the crankshaft. Therefore, we start the engine immediately after connecting the additional battery. Moreover, you may have to turn off a dead battery altogether. Having applied the auxiliary voltage to the network, we start the engine, then we connect the dead battery and then turn off the auxiliary one.
If trouble is found in the garage, where there is electricity and a starter charger, first connect it to a discharged battery, and then to a power outlet - this will reduce the risk of damaging the vehicle's on-board network. Made? Now we pause for 20-30 minutes so that the battery revives a little - and only after that we start the engine. To reduce the load on the battery, we leave the starting charger on: it will take on some of the load.
Sometimes it’s better not to “light up”
When is “lighting up” justified? When you are confident that the discharged battery is working properly. For example, when trying to turn on the starter, its relay clicks, and the battery itself has recently been discharged (the usual reasons are they forgot to turn off the heating, etc., or they barely crawled in traffic jams where the generator was running at minimum speed, and the load on it was high).
If the battery is hot to the touch, emits a strong smell, you cannot light it. Inside, intensive electrolysis of water must have taken place with the release of free hydrogen and oxygen. And this explosive mixture can go bang from an accidental spark! It is also impossible in the case when electrolyte flows out through damage to the case. The plates are exposed, "hover", again, an explosive mixture may form. A battery that suddenly failed for no apparent reason is no better. Most likely, there is an internal defect - unreliable contact in the bridge between the banks. If you connect a well-charged battery to such a battery, it can cause a spark inside, enough to explode.
One more rule. If the donor's battery has confidently turned the crankshaft of your car three times, and the engine has not given any flashes, further attempts are usually pointless. We'll have to look for faults - most likely they will be found in the ignition and power supply systems of the car. Sometimes it's not that simple. For example, the ignition module has failed, and the fuel supply is in order - because of this, when trying to start, the candles were flooded. In this situation, even after replacing them, it will not be possible to start the motor.
If the car has been parked for a long time with the battery connected (in the warm season - more than a month), then it is probably already damaged by sulfation - it can be gradually reanimated with a small charging current, but this procedure takes time and patience. In our age, such batteries are simply thrown away.