What can 6,000 electric vehicles tell us about EV battery health?

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Well-known member
Mar 24, 2013
Fairfield County CT
This article from Geotab is worth reading:

What can 6,000 electric vehicles tell us about EV battery health? https://www.geotab.com/blog/ev-battery-health/

It's rather long but the conclusions should sound familiar:

"Tips to prolong your EV battery’s life

While battery degradation varies by model and external conditions such as climate and charging type, the majority of vehicles on the road today have not experienced significant decline. In fact, overall degradation has been very modest, with an average capacity loss of just 2.3% per year. Under ideal climate and charging conditions, the loss is 1.6%.

While some things are out of an operator’s control, there are ways you can extend the life of your EV’s battery.

Some tips for operating your EVs:

o Avoid keeping your car sitting with a full or empty charge. Ideally, keep your SOC between 20-80% particularly when leaving it for longer periods, and only charge it fully for long distance trips.

o Minimize fast charging (DCFC). Some high-use duty cycles will need a faster charge, but if your vehicle sits overnight, level 2 should be sufficient for the majority of your charging needs.

o Climate is out of an operator’s control, but do what you can to avoid extreme hot temperatures, such as choosing shade when parked on hot days.

o High-use is not a concern, so fleets shouldn’t hesitate to put them to work. An EV isn’t useful sitting idle in the fleet yard, and putting on more miles per vehicle is overall a better fleet management practice.

Final thought: Don’t sweat the small stuff. As vehicles come out with larger battery packs, losing some capacity may not impact your day-to-day driving needs, and shouldn’t overshadow the many benefits EVs have to offer."
What they don't mention very much is how much a TMS affects battery health in warmer climates. Most other manufacturers have a TMS. Not Leaf! Bigger batteries are better than smaller batteries but a TMS is necessary in most of the US. Leafs in warm climates have losses of up to 10% annually despite best practices in battery maintenance.

Improvements in battery technology and size increases notwithstanding, shoddy engineering and cost cutting will negate those benefits.