The Edison battery was more durable than any battery that we are likely to see in our lifetimes. Jay Leno has some Edison cells in his Baker Electric and they still work.
If you could hop into your DeLorean and go back to 1910 to save electric cars the way to do it would be to organize a meeting of the heads of the electric car companies and the heads of the interurban railroads and tell them that unless they convert the interurbans into electric highways for electric cars they will all be toast by 1920. In 1910 there were electric interurban railways connecting every town, today we use them as hiking paths. There were no paved roads outside of cities and gasoline was still being bought at hardware stores instead of gas stations. The interurbans had trolley wires that could have been used for cars instead of trains, those wires were already in place. With electric highways the range problem of electric cars would have been solved, the batteries of the time had enough capacity to handle local driving so if you could put up a trolley pole and get on a highway an electric car could have gone anywhere. Of course nobody at the time could possibly have had the foresight to realize that, the interurbans and electric car companies all went out of business in the 1920s. If Thomas Edison had done what Steve Jobs did with the record companies history might have been different. Just to summarize what Jobs did, when Apple was about to launch the iPod he called the record company heads into his office and ordered them to join iTunes. At the time they were trying to fight Napster by suing single mothers for hundreds of thousands of dollars because their kids had downloaded some music, it’s not a strategy that could possible work. Jobs told them that they would all have to sell their music on iTunes for 99 cents and that Apple was going to take 30 or 40 cents of that. They hated it but Jobs told them that was their only alternative besides bankruptcy so they all fell in line. I could imagine that Edison could have done the same thing, he had the stature to do it, but of course that’s an alternative universe.