Car batteries have a certain life-span and are meant to be replaced over time. That’s a fact that every driver and car owner should have in mind So, how long do car batteries last?
In this article you’ll see what you can expect from your car battery over time as well as some of the main factors that either prolong or shorten the car battery lifespan.
HOW LONG DO CAR BATTERIES LAST?
The average life span of a car battery is from two to five years.
Two years is a bare minimum and even the cheapest, most low-quality car batteries should be able to last that long.
Five years is the real average for a good quality battery under the circumstance that everything else is OK (alternator voltage output, electric installation, and so on).
Some car batteries may even last longer. The longest period I’ve seen is seven years.
But this is just the tip of the iceberg if you really want to understand how long do car batteries last.
You see, besides the predicted duration provided from the manufacturer there are numerous other factors during the exploitation period which seriously affect battery longevity.
They can both seriously shorten or prolong the anticipated battery life.
More about these important factors lower in the article. I recommend to read them if you want to get a complete picture of how long do car batteries last.
WHY DO CAR BATTERIES DIE?
Before we continue, it would only be logical to mention why do car batteries die in the first place?
Well, the reason demands an explanation from the field of chemistry.
Since this is not my field at all, you can get a professional explanation from Wikipedia by clicking here.
But I’ll try to give you a shortened, layman version:
The inner core of the car battery is made out of a combination of lead plates and electrolyte. Electrolyte is the fluid inside the battery which is a combination of distilled water and sulphuric acid.
The interaction between the lead plates and the electrolyte produces a chemical process called electrolysis.
Electrolysis results in the creation of electric current (direct current to be exact).
So, where do the problems begin?
Over time, a process called sulfation occurs on the lead plates inside the battery slowing down and eventually stopping the electrolysis process.
If you were to open the car battery (which I don’t recommend as it is very dangerous) you would see a scale-like build-up (sulfation) on the battery plates.
This is what stops the chemical process as the plates simply get clogged and the interaction with the electrolyte is weakened.
No electrolysis, no electric power.
The whole problem naturally occurs so to speak and no car battery of this type is immune to this process.
It simply has to ˝die˝over a certain period of time.
HOW LONG DO CAR BATTERIES LAST-MAIN FACTORS
1. ALTERNATOR VOLTAGE OUTPUT
The car battery is an initial source of electricity.
It gives the car electric power needed to start the engine and to keep the installation powered up while the car is in standstill.
Once the engine is running, the alternator takes over that role providing electricity and recharging the battery at the same time.
Problems like high or low voltage output can severely damage the car battery and influence the longevity of it.
Low voltage means that the alternator is not producing enough electricity so the battery takes over as the primary source of electricity (you essentially drive a battery-powered car). This means the car will run just for a short amount of time before the battery is totally out of electricity.
Higher voltage can cause severe damage to the lead plates inside the battery and eject electrolyte out of the battery. I don’t mean a geyser type ejection, rather a wetness appears on top of the battery. Also, a bad smell appears, similar to rotten eggs.
To prevent or avoid any of these problems, best check the alternator voltage output from time to time.
Also, if you want to read more about the most common alternator problems, click here.
2. PRODUCTION QUALITY OF THE BATTERY
As with every other car part, quality is a huge factor in answering how long do car batteries last.
Quality mainly depends on the materials used to make the battery as well as the production technology.
Usually brand name manufacturers in this field use high-quality materials which makes them better than their less-known counterparts.
Not saying that a car battery from a less-known manufacturer is garbage, but in most cases brand names are simply more longlasting.
Brand names are also usually more expensive but in the case of how long do car batteries last, some more spent money, in the beginning, means less in the future.
One more factor of how long do car batteries last is the climate.
The main factor is temperature. Car batteries don’t like neither very high nor very low temperatures.
Constant high temperatures increase the possibility of internal scale build-up and even, in more severe cases, evaporation of the electrolyte.
On the other hand, cold temperatures significantly reduce the initial electric power output of the battery. The main reason is that the electrolyte becomes dense making it much more difficult to produce electric power through electrolysis.
The best working temperature is in the mid-range.
So, how does maintenance influence how long do car batteries last?
There are two types of car batteries on the market:
Non-maintenance batteries mean you can’t reach the openings on top of the battery cells to add distilled water or new electrolyte.
Simply, it’s not meant to be tampered with. Most of today’s car batteries are like this.
They will serve well if the conditions are optimal (no damage from the alternator, installation, or else).
If not, one of the first things that will occur in the battery is a low level of electrolyte.
Since it’s sealed up, you can’t add any which will inevitably lead to shortening the battery life.
Car batteries that allow maintenance
These have visible caps on top of the battery which you can open and add distilled water or electrolyte.
In case of low electrolyte level you can open the caps, add some and significantly prolong the battery life-span.
In the case of total power depletion, it can be revived successfully to some point.
All in all, a much more user-friendly option.
One more important thing for maintenance:
Make sure that the battery terminals and poles are always clean and corrosion-free
If you want to see how to properly clean the battery terminals and poles on your car, click here for a separate article on that topic.
5. CAR BATTERY DRAIN (AKA ELECTRIC LEAK)
Battery drains are those small discharges that are barely noticeable but, over time, completely deplete the car battery.
The battery is meant to ˝hold˝electricty for a certain period of time and provide enough electricity for devices that run without the ignition on(like the clock, side-lights, certain electronic components, and else).
Any power-draining besides this puts extra strain on the battery and eventually causes a complete depletion. A few times of this means the end of the car battery life.
6. FREQUENT TOTAL DISCHARGE OF THE CAR BATTERY
By total discharge I mean getting to the point that there is absolutely no more electricity in the battery whatsoever.
Total discharge happens in cases of long cranking, leaving the headlights on for a long time, leaving the radio on, etc.
This will certainly spell doom for the battery. Even the most quality ones can endure maybe a couple of this ˝tortures ˝ before totally giving in.
Frequent total discharge causes damage to the inner lead plates as well as increase the possibility of internal corrosion.
7. DRIVING HABITS
Do driving habits really affect how long do car batteries last?
Certainly, especially in cases of often short distance driving.
Short distance driving means frequent cranking, turning on and off various devices (like lights, wipers, AC,) and else.
Don’t mean that the battery will die on you because of this kind of driving but know that you’re putting serious some strain on it.
You see, the alternator needs some time to recharge the battery and revive it.
If you neglect this fact, you can and will shorten the life span of your battery. This is especially noticed during winter temperatures when short distance driving can cause total depletion.
The remedy for this is to drive the car a bit longer even if it’s not on your route. This way the alternator will have enough time to do its job properly.
Well, hopefully, the answer to how long do car batteries last has been answered.
Again, maybe more important are factors that influence the longevity of the battery rather than the car battery itself.
You can buy a well-made battery from a good manufacturer and pay lots of money but if you don’t take care of it (as well as for the rest of the electric installation and devices), it won’t last long. Certainly not as long as it’s originally meant.
For the end here’s a brief recap and some last useful information:
CHECK THE ALTERNATOR VOLTAGE FROM TIME TO TIME (AT LEAST ONCE IN EVERY TWO MONTHS)
BUY CAR BATTERIES FROM WELL KNOWN AND QUALITY MANUFACTURERS
IF YOU LIVE IN PARTS OF THE WORLD WITH HARSH CLIMATES (EITHER COLD OR HOT) KNOW THAT THE BATTERY MAY HAVE A SIGNIFICANTLY SHORTER LIFE-SPAN THEN IN NORMAL CLIMATE
IF YOU HAVE THE POSSIBILITY OF MAINTAINING YOUR BATTERY, DO SO REGULARLY. THIS IS A HUGE FACTOR FOR BATTERY LONGEVITY
SOLVE ANY BATTERY DRAINS AS SOON AS POSSIBLE. THEY CAN BOTH DAMAGE THE BATTERY AND EVEN WORSE, LEAVE YOU SUDDENLY STRANDED ON THE ROAD. (THE CAR WON’T BE ABLE TO START)
IF POSSIBLE, NEVER CRANK THE ENGINE TO THE BITTER END IF IT WON’T START AS USUAL. ALSO MAKE SURE TO TURN OFF ALL OF THE DEVICES WHEN EXITING THE CAR (REGARDLESS IF THEY WORK ONLY WITH THE IGNITION ON)
IF YOU DRIVE SHORT DISTANCES (ESPECIALLY IF YOU LIVE IN COLD CLIMATE), PERIODICALLY DRIVE THE CAR FOR A LONGER DISTANCE. THIS WILL ENABLE THE ALTERNATOR TO PROPERLY RECHARGE THE BATTERY.
Written by: Sibin Spasojevic
Former car technician, life-long car and DIY enthusiast, author for Despairrepair.com