"fred" wrote in
:

it will only last one year

Having had motorcycles since I was 17, I'd say that was a fair statement.
One year might be stretching it a bit...(c;

But, here, we're talking about deep cycle, truly rechargeable wetcells that
one can make last for 5 to 10 years, even under heavy use.

The problem is the ions in the electrolyte combining with the impurities,
say iron or some other metal in solution, in the tap water....eating away
at the available acid supply while not producing usable electrons and not
being recoverable....leading to boat batteries that last a year like cheap
motorcycle batteries...(c;