Should I be charging my EV to 90% each day if I only drive a short distance?

Summary

In this video, the host explores how to maximize the lifespan of electric vehicle (EV) batteries, particularly focusing on lithium-ion batteries. By referencing data from Battery University, the video explains how factors like depth of discharge, maximum charge, and charging speed impact battery health. The host advises that charging a battery to around 60-65% and avoiding full discharges or rapid charging can significantly extend battery life. He shares his personal strategy for optimizing battery usage and encourages viewers to adjust their charging habits for better battery longevity.

Takeaways

• 🚗 The average Australian travels less than 20 kilometers per day in their car, suggesting that many people drive short distances daily, similar to other developed countries.
• 🔋 Fully charging or discharging lithium-ion batteries daily can shorten their lifespan, as indicated by research from Battery University.
• 📊 The depth of discharge significantly impacts battery life. Regularly discharging a battery by 100% results in only about 300 charge cycles, while limiting the discharge to 10% can extend the battery's life up to 6,000 cycles.
• 🚙 Most electric vehicles (EVs) today use nickel manganese cobalt (NMC) battery chemistry, which is sensitive to deep discharge and overcharging.
• ⚡ Charging at high-speed chargers frequently can reduce battery life, making slow or trickle charging a better option for battery longevity.
• 🔋 Maintaining a maximum state of charge at around 60-65% can significantly increase the battery lifespan, with up to 2,400 to 4,000 charge cycles possible.
• ❄️ Storing batteries at high temperatures (above 30°C) or at a high state of charge can degrade battery life, with up to 20% loss in capacity in a year if stored fully charged at 25°C.
• 🧪 Research suggests that limiting the depth of discharge and maximum charge level can dramatically increase battery lifespan, as demonstrated by controlled tests.
• ⚖️ Balancing a lower maximum charge (e.g., 75%) and a reduced depth of discharge (e.g., only using 10% of the battery's capacity) could extend battery life by several years.
• 🛠️ The presenter personally decided to maintain a 60% maximum charge level and recharge only when the battery reaches 40%, aiming to stay within the ideal charge range for optimal battery health.

Q & A

What is the average distance traveled by Australians each day according to the video?

According to data from the Australian Bureau of Statistics, the average Australian travels less than 20 kilometers each day.

Why does the speaker believe that fully charging or discharging a Lithium-ion battery daily might not be ideal?

The speaker believes that fully charging or discharging Lithium-ion batteries daily can shorten their lifespan, based on information available in the public domain.

What is the primary source of information the speaker refers to for battery research?

The speaker refers to Battery University as a primary source of information on Lithium-ion batteries, particularly the document 'BU808: How to Prolong Lithium-Based Batteries'.

What is 'depth of discharge,' and why is it important for battery longevity?

'Depth of discharge' refers to the amount of energy taken from the battery during regular use, expressed as a percentage of the fully charged battery. It's important because deeper discharges reduce battery lifespan. For example, discharging a battery by 100% frequently would result in only 300 cycles of life.

What is the optimal state of charge for Lithium-ion batteries according to the research?

The optimal state of charge for maximizing battery lifespan is between 60-65%. Charging a battery to only 60-65% can result in a significantly longer lifespan compared to fully charging it.

How does fast charging affect Lithium-ion battery longevity?

Fast charging, such as using a supercharger daily, can shorten the battery’s lifespan compared to slower, low-speed charging methods, which are better for the battery's health.

What impact does storage temperature have on battery life, especially for stored vehicles?

High storage temperatures, especially above 30°C, combined with a high state of charge (above 4.1 volts per cell), can significantly degrade the battery over time, even more so than frequent cycling.

How does reducing the maximum state of charge impact battery life?

Reducing the maximum state of charge to 85% or lower can substantially increase battery life. For instance, charging to 85% rather than 100% can double the number of charge cycles.

What is the longest potential battery lifespan according to the data shared?

The longest potential battery lifespan, shown in the orange line of the chart, could exceed 23 years if the battery is only charged to 75% and discharged by 10% each cycle.

What changes has the speaker made to their personal charging routine after reviewing this information?

The speaker has adjusted their Tesla’s charging settings to a maximum of 60% and now charges less frequently, allowing the battery to drop to 40% before recharging. This keeps the battery hovering around the ideal 50% state of charge, which they believe will prolong the battery's life.