From my EXTREMELY LIMITED understanding, sealed lead acid batteries (ie, maintenance free) are simply batteries that are sealed to prevent the normal Joe Schmoe from having to check electrolyte levels. However, they ARE able to lose gases due to venting, such as when recharge state creates too much pressure inside the battery -- again, as I understand it, from charging too rapidly. Venting pressure now and then ends up leaving the battery a bit low on electrolyte.
I've seen videos where people have drilled through the housing, replaced electrolyte, then sealed their holes. Seems I also saw one where a guy was able to pry the top completely off of the battery, then replaced it later. In all instances, those batteries were shown to be bad, so nothing to lose.
There's an interesting article on Wikipedia about batteries:
In a valve regulated leadacid (VRLA) battery, the hydrogen and oxygen produced in the cells largely recombine into water. Leakage is minimal, although some electrolyte still escapes if the recombination cannot keep up with gas evolution. Since VRLA batteries do not require (and make impossible) regular checking of the electrolyte level, they have been called maintenance free batteries. However, this is somewhat of a misnomer. VRLA cells do require maintenance. As electrolyte is lost, VRLA cells "dry-out" and lose capacity. This can be detected by taking regular internal resistance, conductance or impedance measurements. Regular testing reveals whether more involved testing and maintenance is required. Recent maintenance procedures have been developed allowing "rehydration", often restoring significant amounts of lost capacity.
VRLA types became popular on motorcycles around 1983,[27] because the acid electrolyte is absorbed into the separator, so it cannot spill.[28] The separator also helps them better withstand vibration. They are also popular in stationary applications such as telecommunications sites, due to their small footprint and installation flexibility.[29]
Sure would like a little more info on the part in BLUE.
Upload one or more videos to your post. Photo and video filesizes should be less than 8MB. Formats allowed are gif, jpg, png, ogg, mp4, mov, and avi. Be sure to use filenames without spaces or special characters, and filetypes of 3 digits lower case.
We sell tractor parts! We have the parts you need to repair your tractor - the right parts. Our low prices and years of research make us your best choice when you need parts. Shop Online Today. [ About Us ]
Today's Featured Article - On the Road with Dave Gohl: Deere Departed Friend - by Dave Gohl. Have you ever had to part with a dear friend? It's not easy. If it's due to death, your feelings could be in disarray for days, months or even years. Even now after almost 4 years, I still miss my dad. I remember when I was a kid my dad sometimes would tuck my brother and I in at night and we would ask him questions about his childhood on the farm. To this day, it's some of the best stories I've ever heard. And now, I'm so glad that I asked those questions, and if I were a little smarter i
... [Read Article]
Latest Ad:
1965 International Harvester McCormick Farmall cub tractor 2,500. Two owner tractor. My grandfather bought new in 1966, then we inherited it. Have all the paperwork original manual and all maintenance records. It starts and moves. Comes with underbelly mower, plough, and some other attachments.
[More Ads]
All Rights Reserved. Reproduction of any part of this website, including design and content, without written permission is strictly prohibited. Trade Marks and Trade Names contained and used in this Website are those of others, and are used in this Website in a descriptive sense to refer to the products of others. Use of this Web site constitutes acceptance of our User Agreement and Privacy Policy
TRADEMARK DISCLAIMER: Tradenames and Trademarks referred to within Yesterday's Tractor Co. products and within the Yesterday's Tractor Co. websites are the property of their respective trademark holders. None of these trademark holders are affiliated with Yesterday's Tractor Co., our products, or our website nor are we sponsored by them. John Deere and its logos are the registered trademarks of the John Deere Corporation. Agco, Agco Allis, White, Massey Ferguson and their logos are the registered trademarks of AGCO Corporation. Case, Case-IH, Farmall, International Harvester, New Holland and their logos are registered trademarks of CNH Global N.V.