Old cars 1794
Well, yes and no.
Maintenance- free car batteries of the wet, lead-acid variety have different alloys and more water on top than the old-fashioned ones so as to have a fighting chance of making it through the warranty period without maintenance. Though batteries really are better than they used to be, their manufacturers are as happy as ever to sell you a new one...
*** Observing all safety precautions ***, you can prise the covers off the two rows of holes to see how they're doing, and add distilled water if need be, just as in days of old.
Those who really know what they're doing can even get a battery hydrometer to check the specific gravity, look up what it should be vs. temperature, and adjust it with extra acid if need be. Many authorities caution that Joe Average, or even Joe Above Average who puts an average battery to average use, should stick with the water, though.
See for instance and
Old cars 1796
I bought 4 cars from them, including the van I was driving. They did lose...
Maintenance "free" or otherwise, this should not be confused with an absorbed-glbutt-mat battery. That kind of battery cannot and need not be opened. It is popular with people who want a lighter car for higher performance, drive in horrid conditions, or just want to treat themselves to a deluxe item at maintenance time. The reasons: in addition to being maintenance-free, it is substantially lighter, and, if properly constructed inside, supposedly quite a bit tougher in physically harsh conditions, compared to a traditional wet lead-acid battery of similar power. Substantially spendier, too.
These automotive starting batteries (and many, perhaps most, deep-cycle batteries for vehicles) are also not to be confused with the sealed lead-acid batteries often found in backup power supplies for computers, etc.
Just a few of the many ways to store electricity and perhaps carry it around...
--Joe "Form follows function... and expenditure is always nipping at their heels" Chew
Old cars 1795
The most impressive set of batteries I've seen so far, are the ones at the breaker house at Long Branch station in NJ (NJT). Nice big gen-u-ine Lucent, i.e. 'phone company...