How To Ruin Your Electric Car's Battery - LFP Edition!

Summary

This video explores best practices for extending the life of lithium iron phosphate (LFP) batteries in electric vehicles, contrasting with nickel manganese cobalt (NMC) batteries. It clarifies misconceptions, emphasizing the importance of charging to 100% periodically for calibration, yet recommends lower charge ranges for longevity. The video references a study by Jeff Dahn, a leading battery researcher, which advises against frequent high-charge cycling for LFP batteries. Viewers are also cautioned against completely draining batteries, as it can cause permanent damage.

Takeaways

• 🔋 The electric car market is currently dominated by Nickel Manganese Cobalt (NMC) batteries, but Lithium Iron Phosphate (LFP) batteries are expected to surpass NMC by 2028.
• 📚 Ford's electric crossover, the Mustang Mach-E, makes it easy to identify the battery chemistry through the vehicle identification number (VIN), with specific digits indicating LFP or NMC batteries.
• ⚠️ Ford recommends setting the maximum charge level to 100% for LFP batteries and charging to 100% at least once a month to maintain range accuracy, which is contrary to the advice for NMC batteries.
• 🔍 The voltage curve for LFP batteries is flatter compared to NMC, making it difficult to determine the exact state of charge without reaching the full 100% charge.
• 🔄 A study from Jeff Dahn's lab, known for its work with Tesla, suggests that cycling near the top of charge (75% to 100%) is detrimental to LFP battery longevity.
• 🔌 The study recommends operating LFP cells at lower states of charge for long-term applications, with occasional charging to 100% to maintain calibration.
• 🚗 For those without home charging facilities, LFP EVs might be more suitable due to the need for regular full charging and the benefit of draining the battery further down between charges.
• 🔄 Tesla's recommendation for LFP battery EVs is to keep the charge limit at 100% and charge fully once per week, avoiding small charge cycles at the top end of the battery's capacity.
• ❌ It's important not to let the battery get down to 0%, as this can cause permanent damage, and manufacturers usually build in a buffer to prevent this.
• 🛠️ The best practices for battery longevity are not necessarily the same as the best overall practices, and manufacturers often provide advice that balances longevity with convenience and performance.
• 📈 The study findings are based on testing at elevated temperatures, which accelerate degradation, but still provide valuable insights into battery longevity under different conditions.

Q & A

What is the current dominant battery chemistry in the electric car market?

The current dominant battery chemistry in the electric car market is Nickel Manganese Cobalt, or NMC batteries.

What is the expected future of Lithium Iron Phosphate (LFP) batteries in the electric car market?

It is expected that LFP batteries will surpass NMC batteries by the year 2028.

What is the significance of the 'F' being silent in the term 'LFP'?

The 'F' is silent in 'LFP' to indicate the chemical composition of Lithium Iron Phosphate, which is pronounced 'lif-poe'.

Why is it important to understand the battery chemistry of an electric car for best practices?

Understanding the battery chemistry is important because the best practices for ensuring battery longevity differ between LFP and NMC batteries.

What does Ford recommend for maintaining range accuracy in their electric vehicles with LFP batteries?

Ford recommends setting the maximum charge level to 100% and charging to 100% at least once per month for maintaining range accuracy in their electric vehicles with LFP batteries.

How does the voltage curve of LFP batteries differ from NMC batteries?

LFP batteries have a much flatter voltage curve compared to NMC batteries, which have a steeper slope. This difference affects how accurately the battery's state of charge can be determined.

What is the recommended state of charge for LFP batteries when storing them for an extended period of time?

For extended storage, Ford recommends maintaining the state of charge of LFP batteries at approximately 50%.

What is the main conclusion of the study conducted in Jeff Dahn's lab regarding LFP batteries?

The study concluded that cycling near the top of charge (75 to 100% state of charge) is detrimental to LFP graphite cells, and time spent cycling at high states of charge should be minimized for longevity.

What is the recommended best practice for operating LFP batteries for long lifetime applications according to the study?

The study recommends operating LFP cells at low states of charge on average, with charging up to 100% only on occasion for long lifetime applications.

Why is it suggested to only plug in an electric car when you need to?

Plugging in the car only when needed can help avoid small charge cycles at the top end of the battery, which is detrimental to LFP batteries, and can also be more convenient for those without home charging facilities.

What is the general advice from Tesla regarding charging their electric vehicles with LFP batteries?

Tesla recommends keeping the charge limit at 100% and charging fully once per week, which helps avoid small charge cycles at the top end of the battery and also ensures the battery's actual state of charge is accurately known.