Paul1944 wrote:
Maybe there are other maintenance-free batteries that I don't know about.
By careful about the term "maintenance free". Many flooded (wet) lead acid batteries are labeled "maintenance free" because their caps are designed to "capture" any moisture that is vented and return it to the individual cells. Technically, these types of batteries
(commonly used as the chassis battery in most vehicles) SHOULD have their fluid level checked
(typically requires a tool to pry off the caps) at least once a year while you are cleaning the outside of the battery.