Battery care
What actually
matters
Most battery advice is repeated without anybody checking it. Here is each piece with the evidence behind it named.
At a glance
- Heat is the one factor with no argument attached
- The 20 to 80 rule is real but oversold, and it inverts for iron phosphate
- Fast charging is genuinely contested, and two large studies disagree
- Reconditioning is a myth on lithium and real on older hybrids
- The 20 to 80 ruleGeotab found no meaningful penalty for using a wide range. What did show up was habitual extremes. Cars that spent more than 80 percent of their time
- How often you can fast chargeRecurrent looked at 13,000 Teslas across 160,000 data points and found no statistically significant difference between cars fast charged more than 70
- Heat and where you parkPark in shade where you can and avoid leaving the car at 100 percent in summer heat. High state of charge and high temperature compound rather than si
- What winter actually doesAcross 30,000 vehicles, cars returned about 78 percent of rated range at 32 Fahrenheit and about 70 percent at 20 Fahrenheit. A heat pump recovers rou
- PreconditioningHeating the cabin and the pack from the wall rather than from the battery is free range. Arriving at a fast charger with a cold pack is the most commo
- Leaving it parked for a long timeAround 50 percent is the usual advice, or 70 to 80 percent if the car stays plugged in over winter. Do not store at 100 percent and do not store near
- Battery conditioning and reconditioningBalancing on a lithium pack is automatic and continuous, so there is nothing for an owner to initiate. A full charge on an iron phosphate pack helps t
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