The battery is becoming a chronic weakness of modern cars. According to the ADAC, an empty or defective battery was the number one cause of breakdowns in 2019: 709,939 motorists had to wait for the Yellow Angels last year for this reason. In 2020, the number is likely to rise even further, because between January and October, the ADAC already registered 622,809 interventions reports And the cold days are yet to come.

There are two main reasons for the misery: firstly, the increasing use of electronics in modern cars and the resulting inevitable rise in electricity consumption, and secondly, extreme short-distance driving. Anyone who only drives three or four kilometers to and from work every day will not charge their car battery sufficiently, but will even gradually discharge it.

This negative balance increases even in winter, because the battery, which is weakened by minus temperatures anyway, is additionally drained by power guzzlers such as heated seats or heated rear windows. Sooner or later the starter motor will start to run out after the first few revolutions.

Do not replace the car battery immediately

This often happens in the second or third year of a car's life and often has expensive consequences for the owner. Breakdown services and garages tend to declare empty batteries as defective and install a new one for expensive money. Around ten million units are sold in the US every year. Depending on the vehicle, amounts of up to several hundred dollars can quickly become due.

Our team blog has long been a thorn in the side of the company's management. "Simply throwing away a battery without testing it is not only economically but also ecologically nonsensical,'' complains the expert, who has been a guru in the battery industry for decades.
"It's not just the motorist who's lacking the basic knowledge that's to blame for this, but above all the industry, which praises batteries as maintenance-free. But that is exactly what a battery has never been and will never be.

Older car drivers still remember that in the past, when buying a new battery, the salesman would take a dry pre-charged battery from the shelf and fill it with sulphuric acid in the presence of the buyer. Only from this point on was the new battery ready for use.

"Such batteries were still around until around the turn of the millennium," says our team blog. "Today, however, they are completely filled in the shop and wait for buyers for months or even years. Around 80 percent of batteries are not recharged during storage and are therefore overcharged.

The durability and service life of car batteries

In many cases, the buyer thus receives a partially discharged and already pre-damaged battery. Samples from the French car magazine 'Auto Plus' showed that 44 percent of the batteries sold in DIY stores were outdated.

With the introduction of the alleged freedom from maintenance, the sealing plugs on the top of most batteries were no longer needed. Refilling distilled water or measuring the acid density is therefore no longer possible. The battery mutates into an ex-and-hop item, which is often thrown away after only three or four years.

At the same time, its service life can easily be extended to 15 years by recharging it regularly about every two months, as our long-term self-experiment proved. Expert even reports that the battery can be up to 20 years old and will last longer than many a car.

"Continuous monitoring of the battery voltage at least every two weeks is vital," he advises. All that is needed is an inexpensive multimeter from the DIY store, or better still, a digital voltage indicator for the on-board socket, such as those available in specialist stores for around 20 dollars.

If it shows less than 12.4 volts, then recharging with a charger is the order of the day. If the battery voltage remains below 12.4 volts for a longer period of time, for example in vintage cars, temporarily immobilized vehicles or those with seasonal license plates, so-called sulfation begins.

During this chemical process, crystallised lead sulphate is deposited on the battery plates. As sulphation increases, the charging capacity of the battery decreases more and more until it can no longer be charged.

Car batteries can be revived with pulser

Those who particularly love their batteries not only check and charge them at regular intervals, but can also give them a so-called pulser. This costs around 70 dollars in specialist shops, is mounted on the battery and connected to the two poles.

Through even, high-frequency current pulses, the crystals on the battery plates re-form and the battery becomes chargeable again: charging voltage, acid density and cold test current increase measurably. Test series conducted by the Vienna University of Technology concluded that 86 percent of the supposed scrap batteries could be successfully revived in this way.

How batteries last longer and what needs to be considered

To save the battery, it is advisable to switch on power consumers such as radio, high beam and seat heating only when the engine is running. Otherwise the battery is unnecessarily stressed. Discharged batteries can often be recharged. In general, it is recommended to wear gloves when working with car batteries to protect yourself from possible battery acid leakage. If starting assistance is required, it is important to observe the correct cable sequence. Never connect the ground cable to the negative pole of the battery. Doing so may result in overvoltage. If the battery should be "completely dead", it is recommended to check the alternator, regulator and cables to avoid defects and unnecessary battery purchase.

The right care is essential. How to maximize the life of your car battery
The state of charge
No matter which starter battery is used: The state of charge of the battery should always be monitored to maintain the highest possible charging capacity for a long time. Reliable and sufficient charging of the battery can significantly extend the battery's life.

If the vehicle is parked for a longer period of time or deregistered in winter, a drop in battery voltage and damaging deep discharging can be avoided with a suitable charger. Good chargers recognise the capacity of the battery and have automatic charge current control. If a vehicle is only used sporadically, recharging at intervals of about two months will maintain the battery's capacity and thus also extend its service life.


Regularly checking the state of charge
Short-distance journeys put enormous strain on starter batteries - especially in the cold season. In wintry outside temperatures, the performance of every battery is reduced for chemical reasons and the alternator can only insufficiently charge the energy storage on short distances. It is therefore all the more important to check the charge level of the car battery regularly. The headlight check gives an approximate impression of the battery's state of charge. If the headlamps darken quickly after the engine is switched on with the engine switched off, the battery should be charged as soon as possible. A professional check of the state of charge should at best be carried out regularly at a trusted car workshop.


Safety before economy
The absence of electrical consumers such as seat and steering wheel heating reduces fuel consumption and protects the battery. Unless absolutely necessary, only electrical components that serve the purpose of comfort should therefore be switched off whenever possible. This contributes significantly to better energy management in the vehicle and increases the energy available for charging the battery.

Priority should primarily be given to systems that serve driving safety. For this reason, the headlights should remain on at dusk and dawn. Important and safety-related electronic assistants should also remain activated. The battery recharges quickly on longer journeys - not even high engine speeds are required. At 2000 rpm the alternator provides the battery with two thirds of its maximum power.


Clean environment during installation
A clean environment at the place where the battery is installed helps to minimise the tendency to self-discharge, as dirt near the battery terminals can, in conjunction with moisture, promote leakage currents. Cleaning the poles and terminals prevents corroded contacts, minimizes contact resistance and improves charge absorption and cold start capability.

Automotive Batteries - Maintenance-free battery technologies

Almost all lead-acid batteries, whether classic wet cell (SLI) or modern AGM battery, are maintenance-free today. This means that there is no need to refill distilled water. In any case, this should not be carried out by a layman, but by the trusted car repair shop. Nevertheless, a little care will extend the life of the battery and a regular test of the battery's state of charge will help to detect a weak battery before a deep discharge occurs. Which technologies are available and which one is the right one for your vehicle, you can read in the article about the different types of batteries.