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Battery life in electric cars

January 9, 2025 By EarthWise Leave a Comment

Most of us have lots of experience with the batteries in phones, computers, and other gadgets. Batteries don’t last forever, and we sometimes have to replace them. It’s a fact of life. These days, it’s becoming more common to drive electric cars and the fundamental principle is the same. However, the battery pack in an EV is the most expensive part of the car, so its reliability and lifespan is a greater concern.

EV batteries generally have generous warranties. In the US, EV batteries are required by federal law to be covered for at least 8 years or 100,000 miles, whichever comes first. So, the financial exposure from the battery pack is reasonably limited. Even so, EV owners would like to know that their car’s battery pack is likely to last a long time.

Battery life is generally determined by laboratory tests involving repeated charge-discharge cycles over a relatively short period of time, as opposed to those cycles being spaced out over years.

A new study by Stanford University looked at battery performance under conditions much more like what would be experienced in the real world. Cars experience frequent acceleration, braking that charges the batteries a bit, lots of stops, periods of rest, and so forth. Nothing like just charging and discharging repeatedly.

The study found that today’s EV batteries may last up to 40% longer than expected. Real-world stop-and-go driving benefits batteries more than standard test conditions.

The cost of EV batteries continues to get lower all the time and it is likely to be quite a long time before one is likely to need a new battery assuming one even keeps the car long enough.

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Existing EV batteries may last up to 40% longer than expected

Photo, posted August 27, 2021, courtesy of Ron Frazier via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

The Hottest September | Earth Wise

November 5, 2020 By EarthWise Leave a Comment

Here’s a news item that is like many other recent news items: September 2020 was the hottest September since 1880, according to the National Oceanic and Atmospheric Administration. The warm September is a part of a year that so far is poised to be at least the second hottest year in the 141-year climate record.

The ten warmest Septembers on record have all occurred since 2005, and the seven warmest Septembers have occurred in the past seven years.

So far, the year-to-date average global temperature has been the second warmest on record, being just 0.07 degrees Fahrenheit lower than the record year-to-date temperature set in 2016. Expectations are that 2020 will end up somewhere among the three warmest years on record for the globe.

September was warm in many places around the world. California and Oregon had their warmest September ever. Europe had its warmest September on record, Asia had its second warmest September on record as did Australia and South America.

So far, it has been the hottest year-to-date on record in Europe, Asia, and the Gulf of Mexico. No land or ocean areas anywhere had record-cold year-to-date temperatures.

Global temperatures represent an average over the entire surface of the planet. The fact that the global temperature is now nearly one Celsius degree above the 20th century average means that a vast amount of heat has been added in order to warm all the oceans, atmosphere, and land by that much. So, every uptick in global temperature is a big deal.

Meanwhile, the average Arctic sea ice coverage for September was the second smallest on record. The 14 smallest minimum annual sea ice extents have all occurred in the past 14 years.

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Earth just had its hottest September on record

Photo, posted September 2, 2020, courtesy of Tim Vrtiska via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Alaska Is Getting Wetter | Earth Wise

August 31, 2020 By EarthWise Leave a Comment

Siberia has been in the news for record-setting heat waves and wildfires, but it is not the only northern region experiencing unusual weather. Alaska, apart from setting its own warm weather records, is experiencing the rainiest five years in its century-long meteorological record.

Extreme weather in the Arctic is being driven by an aspect of climate change called Arctic amplification, which leads to temperatures rising faster than the global average. The physical basis of Arctic amplification is well understood, but its effects over time are much less predictable.

The past five years included two summers with average precipitation, one that was a little drier than usual, and two of the wettest summers on record. Researchers have taken measurements of how far below the surface permafrost has thawed by the end of summer over a wide range of Alaskan environments.

About 85% of Alaska sits upon permafrost and the increasing rainfall over the past five years is leading to a deeper thaw of permafrost across the state. The wettest summer on record was 2014 and permafrost didn’t freeze back to previous levels even when the next couple of summers were relatively drier.

The study demonstrated how different types of land cover govern relationships between summer rainfall and permafrost thaw. As Alaska becomes warmer and wetter, the vegetation cover is projected to change, and the increasing occurrence of wildfires will disturb larger areas of the landscape. These conditions are likely to lead to a feedback loop driving more and more permafrost thawing.

Fundamental changes to Alaskan ecosystems are occurring on an unprecedented timescale – not gradually over decades or lifetimes, but over mere months or years.

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Alaska is getting wetter. That’s bad news for permafrost and the climate.

Photo, posted June 10, 2011, courtesy of Peter Rintels via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.