Price grid-grade lead-acid batteries just for fun. Ain't cheap. Supposedly caveman simple lead plates in acid but getting the right alloy of lead for deep cycle and long term service is not that simple. I have been studying options for battery backed PV and currently lithium is winning. Lithium permits deeper cycles, more often, than lead. For reliable long term use a lead battery can not be discharged below 50% so one must buy much more lead capacity. So much so that lithium may have a cost advantage, and definitely has a low maintenance advantage.
As a student of Tesla for over 7 years, former investor, and car owner since 2013, I say Tesla does a lot of stupid things. A lot of stupid arrogant "I'm an intellectual and I have thought on the matter and reached the one any only right possible answer!" Such as their automobile production line. They knew everything yet had never built an automobile before. Paid the price.
Hydrogen is a fool's errand. As an engineer I say, "It got us to the moon. But NASA's idea of an acceptable cost is astronomical." Hydrogen is a terribly inefficient energy storage medium. Even if fuel cells drop in cost by 100x the electrical energy to produce H2 by electrolysis is much greater than if one simply stored the power in batteries.
95% of the hydrogen produced today comes from natural gas. Costs too much otherwise.
But use of a battery is not free. There are capital costs and wear costs.
While companies like Tesla may be dumb they are making EV's mainstream technology thankfully. 