Supplied as kits, Halls ' comprehensive range of free-standing and lean-to greenhouses is made from maintenance-free aluminum.
The other is a maintenance-free battery.
Battery type: Unless the manual states otherwise, a maintenance-free battery should never be exchanged for a conventional one.
With a maintenance-free battery, you have nothing to do except keep it clean and make sure the terminals and connections are in good shape.
Solar shingles remain practically maintenance free after they are installed.