How to look after an EV battery
Four habits cover almost all of it, and none of them are onerous. Most advice beyond these is noise.
Battery care attracts more folklore than any other part of EV ownership. The genuinely useful advice is short.
1. Live in the middle
Lithium-ion cells age fastest at the extremes. Sitting at 100% is stressful; sitting near empty is stressful.
Set a daily charge limit around 80% and charge to full only when you need the range. Most cars let you set this once and forget it.
Note the word sitting. Charging to 100% and driving off shortly after is fine. Leaving it at 100% in a hot car park for a week is not.
2. Avoid heat where you can
Temperature matters more than charge cycles for long-term health. Park in shade in summer where practical. Avoid leaving the car at a high state of charge in sustained heat.
Cold is unkind to performance — see winter range — but is much gentler on long-term health than heat.
3. Prefer AC charging for routine use
Rapid charging is what the system is designed for and using it is not abuse. But if the great majority of your charging is DC, especially to high states of charge in warm weather, that will show over years.
Home AC charging is gentler, and dramatically cheaper anyway.
4. If storing it, leave it around half
Going away for a month? Leave it near 50%, not full and not empty. Plugged in is fine if the car can maintain itself.
What does not matter much
Occasional deep discharges. Not ideal, not a catastrophe.
Charging every night. Perfectly fine. Partial cycles are gentler than full ones.
Sitting plugged in. Modern cars manage this properly. It is not overcharging.
What to expect
Roughly 1–2% capacity loss a year, front-loaded — a noticeable dip in the first year, then a slow decline. A five-year-old car at 90% is healthy.
Battery warranties typically run 8 years or 100,000 miles and guarantee against dropping below a threshold, commonly 70%.
Checking your own
Some cars report state of health directly; a dealer diagnostic or a third-party OBD app can read it on many others. It matters most when you come to sell, and when you buy — see the used EV buying guide.
In pictures
Common questions
Should I ever charge to 100%?
Yes, before a long trip, and occasionally so the car can recalibrate its range estimate. What ages a pack is *sitting* at 100%, not reaching it.
Is rapid charging bad?
Occasional use is designed for. Exclusive rapid charging, especially to 100% in heat, accelerates degradation somewhat.
About the author
ElectraMile EditorialEditorial desk
The ElectraMile editorial team covers charging, running costs and EV ownership for readers in the UK and US.
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