Maintenance-Free (MF) Car Batteries...

Should MF batteries come packed with electrolyte and be totaly sealed? My customers always whine that my batteries are not real MF because I have to open them and add the electrolyte (18% H2SO4 solution I believe…).

I know that MF batteries that come with the car are sealed, should this be the case with after-market batteries too? Are my batteries not really MF?

BTW, the batteries I sell are made by Rocket ( I can’t however find the same product numbers in their website. My battery codes have two letters, 5 numbers and then the letters MF for maintenance free, or nothing for plain batteries.

I don’t know the official definitions, but I always equated maintenance-free with sealed, obviously having to come with electrolyte installed. My understanding is that modern batteries that are maintainable are low-maintenance or reduced-maintenance (compared to what was available decades ago). It has been decades since I’ve run across a dry-charged battery – I’m not even sure they’re available here in the States.

Nevertheless, I would say it’s theoretically possible to have a maintenance-free battery with removable caps. In such a case the caps would have to be of the maintenance-free design, specially engineered to virtually eliminate fluid loss over the battery’s lifetime. If the caps are the same as on batteries that are not maintenance-free, I would say the battery company is misusing the term.