“Experiments confirmed that charging at high currents has a huge impact, increasing the lifespan of the average test battery by 50%.”
Factories give new lithium-ion cells a slow first charge that takes about 10 hours. A SLAC and Stanford team ran it at high current in 20 minutes and got 50% longer average lifespan. The hard charge burns about 30% of the lithium up front instead of 9%, and that loss protects the cell for the rest of its life. The industry’s slow default rested on a theory nobody had pinned down.