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Battery costs have declined by 99% in the last three decades, making electrified transport a reality
(ourworldindata.org)
This is a most excellent place for technology news and articles.
Lithium ion batteries are far cheaper now at a consumer level than they were thirty years back.
EDIT: I'm actually surprised that a higher proportion of laptops today don't ship with 100 Wh batteries. Go back some years, and shrinking the battery had a much larger difference in cost than it does today. The larger battery gives you longer battery longevity (makes it more reasonable to charge to 80%, say), can be used to make a laptop run more quickly, can power more devices. The only drawback is weight, and it isn't that heavy.