8 Things You Should NEVER Do With Your EV Battery

Summary

The video explains eight battery-care mistakes to avoid. Its main point is that battery chemistry, vehicle design, and manufacturer guidance matter more than rigid rules.

Eight mistakes to avoid

1. Relying on DC fast charging more often than necessary. Fast charging is useful for EV trips, but frequent high-power charging can create more heat and stress than slower AC charging. The speaker cites a Geotab study of 22,000 EVs, which he says found average degradation of 3% per year for vehicles using DC fast charging at 100 kW or higher, compared with 1.5% for slow AC charging. He cautions that an occasional fast charge is not necessarily harmful.

2. Leaving the battery at 100% for extended periods. For NMC and NCA batteries, spending a long time at a high state of charge can increase cell stress. Charging to full for a trip is fine; the suggestion is to time the charge so the car does not sit full for long. The speaker generally uses an 80% daily limit for his NMC-equipped Kia e-Niro.

3. Leaving the battery nearly empty for a long time. A brief trip to a very low charge level is not necessarily a problem, but a parked EV can continue using some power. If its charge falls below the battery’s actual limits, it may be seriously damaged and become difficult or impossible to recharge. For long-term storage, check the manual. Around 50% is common guidance, though some manufacturers recommend other charge levels or leaving the car plugged in.

4. Prolonged exposure to extreme heat. High temperatures can accelerate unwanted chemical reactions and battery degradation. Modern EVs generally have thermal-management systems, but older vehicles may have less capable cooling. The speaker’s older Nissan Leaf is an example: repeated fast charging in hot weather could cause “rapidgate,” where the car limits charging power to protect the battery. Where practical, park in the shade, avoid leaving a full battery in extreme heat for days, and respond to overheating warnings.

5. Ignoring battery preconditioning before fast charging in cold weather. Cold batteries charge more slowly, and charging too quickly at very low temperatures can cause irreversible degradation through metallic lithium buildup on the anode. Battery-management systems limit charging to protect the cells. Where available, preconditioning warms or cools the battery before a fast-charging stop; it may activate through navigation or manually. The speaker recommends using it when useful, such as before a winter fast charge, rather than for every short trip or slow home charge.

6. Ignoring the battery-cooling system and vehicle warnings. Liquid cooling systems may use pumps, valves, sensors, and heat exchangers. Faults can affect charging speed, range, performance, safety, and long-term battery health. Investigate persistent coolant or battery warnings, and follow model-specific coolant maintenance schedules, software updates, recalls, and service recommendations.

7. Assuming all EV batteries have the same charging rules. The video distinguishes NMC, NCA, and LFP lithium-ion chemistries. NMC and NCA batteries generally benefit from avoiding extended periods at a high charge. LFP batteries are more tolerant of high charge levels, and some manufacturers recommend periodically charging them to 100% so the battery-management system can estimate charge accurately. Check the vehicle’s manual or app rather than relying on generic internet advice.

8. Treating the 20–80% rule as absolute. An occasional charge below 20% or above 80% will not make a battery fail. Long-term habits—such as leaving it full or nearly empty for days, or repeatedly exposing it to extreme temperatures—matter more. Charge to 100% when needed for a trip, and follow guidance for the vehicle’s battery chemistry without letting percentage targets dominate everyday use.

Additional content

• Sponsor segment: UPDF 3.0 is demonstrated for editing and redacting personal information in vehicle reports. The speaker also describes its OCR for scanned documents, AI report summaries, e-signatures, and support for Mac, Windows, iOS, and Android.
• Guide and tutorial elements: The video offers practical EV charging and storage tips. It directs viewers to their vehicle manual and mentions EV Database as a resource for checking battery chemistry.

Main speaker and sources

• Main speaker: Efficient Alex, drawing on automotive-industry experience and ownership of a Kia e-Niro and an older Nissan Leaf.
• Sources cited: A Geotab study, as described by the speaker; vehicle manufacturer manuals and recommendations; and EV Database.
• Sponsored product: UPDF.