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 - A Question for Dads This recent topic from the Tractor Talk discussion board is being highlighted because it is an awesome display of the caliber of individuals that have made this site their own. The young person asking questions received positive feedback and advice from total strangers who "told it like it is" with the care many reserve for their own kids. The advice is timeless... so although it isn't necessarily antique tractor related, it will be prominently displayed in our archives to honor those who have the courage to ask and those who have the courage to respond in an honest, positive manner.
... [Read Article]
Latest Ad:
1964 I-H 140 tractor with cultivators and sidedresser. Starts and runs good. Asking 2650. CALL RON AT 502-319-1952
[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.