What to Do If Your Car Battery Goes Flat on the M-30

Publicado el 18/09/2018
que hacer si el coche se queda sin bateria

Many drivers are unsure of what to do if their battery goes flat when they’re on the motorway. What’s more, in places like the M-30 in Madrid, it may be dangerous due to heavy traffic conditions and high traffic speed. Therefore, as a precautionary measure, it’s good to have a few steps to follow in the event that this happens to you.

Flat battery on the M-30: what to do

First off, a battery has a limited useful life. On average, they last approximately five years. So if your battery is approaching this limit, you should take it to a reputable mechanic to check if it has enough charge, and change it if it’s low. But if you haven’t done so and your car comes to a stop in the middle of the M-30, the first thing to do is keep calm and follow these steps.

Safety recommendations in the event of a breakdown on above-ground sections:

Get the vehicle away from traffic so that it does not block the passage of other vehicles in order to avoid accidents.
Turn on the hazard lights and the parking lights as well if it’s night-time.
If you have to leave the vehicle, put on a reflective jacket and get out on the side furthest away from traffic.
Set up the warning triangles.
Move away from the road and, if possible, stand behind the safety barrier.
Call for help by calling a tow truck, the emergency phone number (112) or use an emergency telephone in the tunnel.
Wait for assistance.


Steps to follow in the event of an accident or breakdown in a tunnel:

Make yourself visible: turn on the hazard lights.
Get to the end of the tunnel until you’re above ground. Do not stay in the tunnel.
If it’s not possible to exit the tunnel, turn on your parking lights, park on the right-hand side of the road and turn off the engine.
Don’t forget to use a reflective jacket both during the day and at night.
Set up warning triangles to alert other drivers.
Call for help by calling a tow truck, the emergency phone number (112) or use an emergency telephone in the tunnel.
Make note of the location codes painted on the tunnel walls. This will help you to give your exact location.
Follow the instructions from the traffic officers over the PA and traffic control system.
Our incident response team will be with you within an average of five minutes.


How to recharge the battery on the motorway

If your insurance provides roadside assistance, you can call the number listed on your policy and ask them to send an assistance vehicle or a tow truck. In both cases, they will bring a booster or jump starter. This performs the function previously carried out by jumper cables, which are not recommended for recharging modern car batteries.

To connect the jump starter to the battery, use the same technique as with jumper cables. Namely, don’t connect the positive to the negative and vice versa and connect the negative terminal first then the positive. Next, activate the booster, wait a couple of seconds so that the petrol or diesel pump can fuel the circuit, and start the car. One you have done this, keeping the engine running, turn off the jump starter and disconnect the terminals, making sure to disconnect the negative first followed by the positive.

The battery is now charging and, as such, the engine cannot be turned off. If you do so, it will not re-start. Therefore, to let the battery recover, you must drive continuously for approximately 45 minutes. If you suspect the battery is at the end of its useful life, the best course of action is to take the car to a mechanic to be checked out.

It is a good idea to know how to do all of this, however if you have roadside assistance, the attending technician will do it for you. However, if you do not have this service, you will have to call a technician directly to take care of the issue.

What if I have a hybrid or electric car?

Logically, it’s different if you have an electric vehicle and the battery goes flat on the M-30. It’s more unlikely that this will happen as these cars have two batteries. In any case, the batteries can only be recharged at the electric car charging points located throughout the city.

However, for hybrids the problem is solved internally, as it is the vehicle itself that charges the electric battery using the petrol engine or braking system.

What not to do if your car battery goes flat

On the other hand, there are some popular techniques for starting cars with a flat battery that shouldn’t be used. The most well-known are:

  • Push starts: often used when the battery dies on a downhill slope. This was useful with older cars but is harmful ever since catalytic converters were introduced. Unburnt fuel comes out the exhaust in this technique and may damage the catalytic converter, which could end up costing more than 600 euros to repair. This is also a dangerous manoeuvre because you won’t have power steering and braking will be more difficult until the car starts.
  • Attaching the car to another car with a rope: this is another technique that was popular in the past but which is no longer recommended for the same reasons mentioned above.
  • Jumper cables: probably the most common technique used when car batteries would go flat. But it is just as harmful. Modern cars have sensitive electronics which need very specific voltages to work correctly. Starting a car with jumper cables causes voltage spikes, which may damage the electronic systems in the vehicle, including the on-board computer. And any damage to these instruments is always very expensive.

Therefore, if your battery goes flat on the M-30, the best course of action is to contact your insurance’s roadside assistance service so that they can take care of it. If you don’t have this service, you will need to call a reputable mechanic.

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