How long do EV Batteries last?

how long do batteries last

Batteries used in electric cars have a wide range of lifespans which depend on the use. Here we will give examples of uses and of the different types.

The most popular battery for use in cars at present is the lithium-ion which can last for 20 years but it’s down to how they are used. This is because a lithium-ion version holds the most electricity for its size and weight out of those currently available. The downside of this is that they are the most expensive of the car type of battery. A typical battery for an electric car in lithium-ion materials will cost anywhere from $4,000 to $20,000. It is therefore the most expensive component of a modern electric car.

Alternative types

When we think of batteries for electric cars, we tend to think only of the LiOn ones already mentioned, but let’s look further. What other kinds are there and what are their pros and cons?

Since the first electric car went on the road almost 200 hundred years ago, ordinary flooded lead/acid batteries as commonly used to start cars, were used in electric cars, but they had 2 major drawbacks. Lead/acid types generally require topping up with distilled water. It is often mistakenly thought that when a battery cell looks empty, it needs acid. The acid is still in the battery but the water component has usually boiled down with use. All we need to do is add distilled water to the correct level (known as a flooded battery). Years ago, electric milk carts and so on used these batteries but there were many accidents and explosions due to incorrect handling and charging. There were also many problems in their use due to them supplying lots of power initially, but power tailing off fairly quickly. Their typical lifespan is 2 to 4 years depending on their uses.

Did you know that the land speed record before 1900 was held by an electric car which topped 60 mph? This was a big shock as petrol cars at the time were unable to exceed more than 20-30 mph maximum. And at the turn of the century in 1900, there were more electric cars than petrol cars. They all used this type of battery.

The problem of the loss of power was improved by the manufacture of what are called “deep cycle” batteries which were also lead/acid but used much heavier components internally and gave power for much longer.

Again this was further improved by using a gel instead of a battery filled with liquid acid. This negated the problem of spillage and in fact, the batteries were then sealed, never needing to be topped up at all to the end of their lives. Gel batteries do not appear to live any longer than 2 to 4 years.

Batteries should NEVER be run down to the point where the motor stops running

Lead/Acid Varieties of Batteries

When the charge indicator in the vehicle shows 50% remaining, it is unwise to take the vehicle out. Charge immediately. The reason for this is that to get the best life out of the batteries, they should be kept fully charged whenever the vehicle is not being used. This will not in the long run cost any more than charging from say 50% to full than it does from 80% to full. The reason is that to charge from 50% will take a long time, but from 80% to full will take a much shorter time. This isn’t the only reason, however. If the batteries are run down to say 50% constantly before recharging, their lifespan will be much shortened due to sulphation inside the battery.

A battery cannot be discharged all the way to zero. When the full charge is 12 volts it can be used until around 10.5 volts is reached on discharge. After that, no power will be delivered and if it continues to discharge without being recharged, it will suffer damage or die completely.

My little electric car is used almost every day for running around town and is always charged on return home. I have noticed only a very small increase in my electricity bill from before I had the car. Probably less than $20 per month. I know this for a fact as in the summer months, my total electricity bill is often little more than $20 altogether. The only other cost is petrol for the onboard generator which I use only when I go over the mountain pass near my home to the nearest large town. The petrol tank is ten liters capacity and I fill it from about 1/3 remaining to full once a month. With my normal running around the town and visits to the town some 16 km away, I have calculated my overall costs at about $28.

A much newer type of battery known as an AGM battery (advanced glass mat) has lifted these lead/acid batteries yet again. They are also of deep-cycle construction but weigh a lot less than gel-type batteries. AGM batteries however are not only lighter but their lifespan has increased from 4 to as much as 8 years. Their cost is about 50% more than standard flooded lead/acid batteries.

Lithium Iron batteries (LiFe). Lithium Iron (not lithium-ion) is another kind of battery which can be used and is used in some of the smaller, cheaper cars. LiFe batteries are an improvement yet again but note that they are a departure from lead/acid batteries. They are lighter and have a life of up to 10 years. The cost of these batteries is about double to one and a half times the price of flooded lead acid batteries.

Lithium Ion, LiOn batteries, are presently at the top of the tree and used in most of the electric cars manufactured today. They pack a great deal of electricity and can last between 10 and 20 years but their cost can makes replacement in the vehicle they are fitted to a big consideration when they die as any second-hand vehicle, petrol or electric, will have a low value at 20 years old and the replacement cost can be from $4,000 to $20,000

This is where the low-cost electric car takes over on secondhand value. After 4 years of daily use, I recently replaced my 6 gel batteries, but not with more gel batteries. I bought AGM batteries for the car. These were more readily available, last up to eight years, which is longer than the gel batteries, cost a lot less than gel batteries, and saved 216 kilos of dead weight. The saving in weight will put less strain on the batteries and on the rest of the car.

Scroll to Top