January 16th, 2020 at 11:06 am
One of the big talking points about new EVs is the ease of charging them and also, how long will the charge last for. This is known in the trade as ‘range anxiety’, after all, if you think of how many petrol stations there are within a five-mile radius of your home and then compare that to charging points, it is a legitimate concern.
Running out of battery is one of the top listed concerns for many motorists who are toying with the idea of switching to this new technology. But, as any motorist knows, you can charge an old battery until the cows come home but if it is nearing the end of its life then it may not have much capacity left full charge or not. As this is your primary mechanism of propulsion, it’s not surprising that sharp-eyed drivers are looking beyond the issue of charging points and are getting more involved in other aspects of battery maintenance and care. Degradation and longevity of the battery is a big question for new drivers.
The battery is one of the most expensive components of the new EV technology so its hardly surprising that is a top concern for a customer who is just about to shell out for what is, after all, not a cheap car.
On the charge
The battery in almost any modern electrical item be it a mobile phone, laptop or EV will have a life and will slowly over time hold less and less charge; this is probably the case for the battery in your current vehicle although most of these are guaranteed for five years from new. The difference of course between the car battery in a traditional engine and that of an EV is both the size and therefore the cost of replacing it. In a standard car, the battery is there to power certain activities and functions, it is not the main means that the car propels itself from.
The batteries in electric cars are of a type called lithium ion known in the trade as LIB – Lithium Ion Battery. These batteries are rechargeable and used well beyond the EV industry so appear in portable electronics and also within the aerospace sector. The technology was first developed during the latter decades of the 20th century and was taken to the commercial market by Sony, the electronics giant.
These batteries work by discharging when you use them and then re-charging when you plug them into a mains source of electricity. Throughout the course of the life of the battery, its ability to re-charge will gradually lessen. It will always be able to be recharged to its full capacity but on an old battery, that capacity may not be any greater than around 20%.
As a new EV owner, what can you do to prolong the life of your car battery?
It’s time to explode some myths here. First off, keeping the battery on a full charge can actually damage it. This because heat is generated during the recharging process. This rather goes against the grain of all those motorists with ‘range anxiety’ who are terrified of running out of charge whilst they are out and about.
Some manufacturers are already on the case and will stop the battery automatically on a recharge when it has reached full capacity. The Tesla Model S saloon will let you charge the car to a certain percentage. It is important not to focus therefore on a 100% charge as this may not actually be in your best interests. Overcharging can also cause chemical degradation within the battery which will affect its life and can also interfere with its ability to hold a charge.
At the other end of the spectrum, a flat or totally discharged battery is also not a good idea. Most LIBs perform best at between 50% to 80% of charge.
Batteries do not recharge evenly. The first 80% of the battery’s capacity will charge more quickly than the last 20% and will really affect your charging times. So it would seem better for your battery health and also quicker, to charge to 80% of capacity only. This might now make more sense of the figures quoted when you read about charging points around the UK and the stats listed to charge a car to 80% capacity rather than 100% capacity.
As any seasoned motorist knows with a conventional engine, cold weather will drain the charge but did you know that heat can also adversely affect a battery? That’s why is best not to leave a battery permanently on full charge too. The batteries in EVs are no different and are subject to the same influences as traditional cars in extreme weather conditions. Battery tests on EVs in a range of temperatures revealed, unsurprisingly. a far reduced range in cold temperatures than in temperate ones. The new EVs have yet to survive a really nasty British winter such as the two the country experienced around a decade ago.
Most car manufacturers are well aware of driver concerns over battery life and are now offering guarantees and warranties of five years or up to 60,000 miles. Tesla is perhaps the market leader in this regard as they offer an eight-year warranty on their Model S without any mileage restrictions and like the manufacturer’s warranty on a standard fuel vehicle, this can be transferred numerous times between different owners so it stays with the car.
Leasing your battery is another option as there is potentially more flexibility in terms of replacement or upgrading as technology develops.
But can you really rely on an EV?
Study the 2019 Reliability Survey by What Car? which covers EV technology. This scores the Nissan Leaf the highest at 99.7% with most of the adverse commentary relating to the condition and durability of the bodywork rather than the battery life. Interestingly, in this class of vehicles, it was the Tesla Model S that was at the bottom of the chart with a score of just 50.9% but again, most of the problems reported were nothing to do with the battery but they are points worth noting. Don’t focus solely on battery quality and life and overlook other issues with the vehicle.