Tips

Flat battery: how to restart it

An inconvenience that happens more frequently in winter, sometimes because of our own mistakes. If your battery leaves you stuck, there are various ways to get it running again

Home Road Cars Tips Flat battery: how to restart it

Touch wood it won't happen, but you never know. A flat battery is one of the situations in which all drivers find themselves at least once in their lives. It is a problem that can happen regardless of the model and make of your car: it can occur due to normal wear and tear or a shorter or longer period of non-use. There are several symptoms that indicate your battery might be about to fail: difficulty in starting your car in the first place, the battery light coming on, or weaker headlights at night. You can hope that the car will send you these signals in good time, but that's not always the case: if you do see the signs, you should take your car to a car electrician as soon as possible to get it checked out and, if necessary, to replace the battery.

How to use jump leads...

If your battery does cut out unexpectedly, unless there is a car electrician nearby who is prepared to come out to your car and recharge it with a booster, you have to use another method to get your engine running. There are two main solutions: connect your car to another one using jump leads so you can transfer the power necessary to restart the engine, or alternatively use a "classic" jump start. Obviously the first option is preferable, ideally using a car whose battery has similar technical specifications to the one in the broken down car. You should position the cars either alongside each other or one in front of the other in order to get the two batteries as close as possible. Next, connect the red cable to the positive (+ symbol) terminal of the assisting car and then the other cable to the positive pole of the broken-down car. Then you connect the black cable to the negative (- symbol) pole of the assisting car to the broken down one. Once this has been done, you should start the car with the charged battery, running the car at a constant rate of about 2,000 rpm. After a few minutes, you can try to start the car with the flat battery, leaving the leads connected.

... or a push start

If the engine of the car with the flat battery does start, you can begin disconnecting the cables in the reverse order to when they were connected. It's a good idea to leave the battery of the broken down car running for ten minutes so the battery can recharge properly. We would still advise you to buy a new battery so you don't soon find yourself in the same situation again. There is also another method: recharging the battery with special powerbanks. There are several types available – you should make sure the powerbank corresponds to the specifications of the battery fitted to the car in question. If you don't have any cables available, the best thing is to get the vehicle moving. You need one person behind the wheel and a couple of volunteers to push the car so it can reach a certain speed, let's say around 10-12 m/h (20 km/h) (it depends on the slope of the road, the area, and the number of people pushing). Once a certain speed has been reached in neutral or with a gear engaged and the clutch down (with the key turned and the instrument panel active), proceed to engage the second or third gear – if it still doesn't engage, suddenly release the clutch. With this method, your engine has a good (though not guaranteed) chance of starting. Obviously, this technique does not work for automatic cars.

Roadside assistance

If this old school method doesn't work either, you have no alternatives left: you have to call roadside assistance. If your car is a short-term rental, the number to call in case of roadside assistance should have been communicated or provided in writing or by email when you signed the contract. It is the same story for long-term rentals, where a 24-hour service is often included in your monthly fee. On the other hand, if you own the car yourself, you might find that roadside assistance is included in your insurance policy. If so, all you have to do is contact someone at the insurance agency, or alternatively check the documentation provided by the insurer to find the right number to call. Otherwise, all you can do is call a recovery truck after a quick search on the internet to find the closest roadside assistance company. And wait for help to arrive!