Funny you say that, with the POS Xantrex charge controller, the first set only lasted 4 years, these are going on 8 years with the MPPT charge controller, and the batteries are always fully charged and I hardly ever have to add water. The Xantrex cooked them and needed water every month, now I need to add water once or twice a year with the MPPT charge controller.
I use solar chargers on a few items. Yes the regulators definitely extend battery life. For some applications solar is the best solution. For national power supply? You got to be kidding me! They are destroying the stability of this country.
If I had my way we would be building nuclear power plants in every state, except for CA, OR, WA, IL, MA,CN, VA….