Myth Busted?
A big question for EV car owners is whether DC (fast) charging will degrade your EV’s battery and from our previous article about Singapore’s EV charging standards, we said yes, it does but its impact is negligible.
Let us explain why.
Based on Geotab’s research, it was found that on average of over 6,000 EVs tested, fast charging causes the battery to degrade at a rate of 2.3% per year.
Another example is a study from Idaho National Laboratory (INL) which carried out an experiment with two pairs of Nissan Leafs that they charge twice daily for a year. One pair only using AC while the other using DC to charge. The results were that the pair that used AC lost 23% of their initial battery life while the other pair that used DC lost 27% of their initial battery life. More information about their experiment can be found here.
So take these questions into consideration:
- How much battery consumption do you use on average?
- How often do you charge?
- What type of battery does your EV have?
- What type of charging stations do you use often?
For example using a MG ZS EV, it has a NEDC combined range of 335km, a battery capacity of 44.5kWh which means an average of 7.5km/kWh.
If you have to drive at least 50km daily, you would have to charge at least once in 6 days or 5 days to be safe.
In 1 year you would have to charge at least 73 times and in 10 years it would be 730 times.
This would mean that by the end of 10 years, your battery would have approximately degrade by 23% using only AC charging and 27% using only DC charging.
So on one hand yes DC charging does degrade your battery but not at a rate which you need to be concern about.
Something you should be more concern about would be the price of Certificate of Entitlement (COE). By the time the degradation of your EV’s battery starts impacting you, the COE of your EV would be expiring.
Still if you are curious about your EV’s battery degradation, you can check out Geotab’s article about it. They have done quite extensive research about EVs and even have a calculator to calculate your car’s battery degradation. Although it doesn’t include all EVs but it is still quite extensive.
I hope this article helps to clear up some misunderstandings about DC (fast) charging and if you have any comments or questions please feel free to leave them below. We will do our best to answer them.
Happy Charging!