Calcium battery

[DaveL]

Probably old news but I thought I would comment on the Calcium battery aspect.  A large number of "maintenance free" batteries sold in automotive applications are the lead-calcium battery.... some have sealed water access ports and some don't.  However most advertise no watering but that is a misnomer.  Even though you will see less water usage, they do eventually need water and ignoring it will result in a failed battery.  Electrically, an automobile would have no distinguishable difference in performance between the two.

As long as the battery is advertised as a "deep cycle" battery then I don't think it really matters whether it it is lead or lead-calcium with the same ratings.