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Metalworking (rec.crafts.metalworking) Discuss various aspects of working with metal, such as machining, welding, metal joining, screwing, casting, hardening/tempering, blacksmithing/forging, spinning and hammer work, sheet metal work. |
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O.T. Battery Charging
This newsgroup has the greatest selection of experts on the web so I hope
you will excuse me for asking an off topic question about charging lead acid batteries. Back in the early 60's when I worked in a service station I was taught to remove the battery caps when charging a car battery so that's how I taught my boys to do it. My son just finished his lift truck training course and they told him to leave the caps on. I checked a number of web sites and they all say the same thing, leave the caps on. My question is have I been doing it wrong for the last 50 years or at one time was removing the caps a standard practice that has since been considered unnecessay or unsafe? Thanks in advance Jimbo |
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O.T. Battery Charging
I believe this has to do with venting hydrogen, I think that most modern
batteries have built in vents that can dissipate this, with out the hazard of having the acid/water exposed. "Jimbo" . wrote in message ... This newsgroup has the greatest selection of experts on the web so I hope you will excuse me for asking an off topic question about charging lead acid batteries. Back in the early 60's when I worked in a service station I was taught to remove the battery caps when charging a car battery so that's how I taught my boys to do it. My son just finished his lift truck training course and they told him to leave the caps on. I checked a number of web sites and they all say the same thing, leave the caps on. My question is have I been doing it wrong for the last 50 years or at one time was removing the caps a standard practice that has since been considered unnecessay or unsafe? Thanks in advance Jimbo |
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O.T. Battery Charging
High charge rates that the gas station battery chargers can do means that
hydrogen does get produced (that is the little bubbles that come up at a rapid rate when charging with those chargers) and that means a nasty explosion if the amount of hydrogen gets high. The thing was to allow the hydrogen to easily get out of the area by first letting it get out of the battery easily. Many chargers can't make the current necessary to get the hydrogen rate up to where it can become dangerous and the sealed batteries have chemicals to adsorb the hydrogen and return it to the liquid by recombining it with the other products of the charging. It's one of those things that you get told to do for a particuar reason and you extend it to all of that particular type of operation in a mindless fashion. -- Bob May Losing weight is easy! If you ever want to lose weight, eat and drink less. Works evevery time it is tried! |
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O.T. Battery Charging
I think the difference between real heavy plated batteries that would
crank a car or truck for an hour to those of today that are both gel cell and thin plates. I had my truck battery replaced - it was a year old after all - and it was replaced with a thin plate junker. It often gives trouble if I don't drive over the weekend or it sits to long or multiple starts without a long charge run. These so called ENVIO batteries are not up to grade. Martin -- Martin Eastburn, Barbara Eastburn @ home at Lion's Lair with our computer NRA LOH, NRA Life NRA Second Amendment Task Force Charter Founder |
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O.T. Battery Charging
Martin,
I must say that you are really off the mark. The construction of car batteries has changed considerably as you have stated, but that construction change has been a real performance booster, not a quality issue. The problem for automotive application is the effective discharge rate of the plates. It has been known for many years that the larger the surface area of the plate is, the higher the discharge current can be without killing the cell. The issue is that the excess electrons on the plate surface are immediately available for discharge, but those excess electrons within the interior of the lead plate must first migrate to the surface in order to be discharged and that takes time. In the past, thin plates of pure lead would fail when subjected to vibration, so a lead alloy was used. The alloying material was antimony and metallic arsenic, which added strength and resistance to vibration. The down size was the alloys also killed durability and cell efficiency. The big change occurred with the availability of high temperature plastics. Today, new batteries are made with a lead filled thin plastic fabric. This has allowed a much larger cell surface area that is exposed to the electrolyte along with a large increase in vibration resistance, overall strength, the use of pure lead increasing efficiency and all this within a much smaller overall size. This change is also the reason why hydrogen outgassing during high rates of charge has also been reduced. That is also why it is no longer necessary to remove the cell caps during the charge process. We now have a new rating system that advertises this change in ability. It is called "The cold cranking discharge rate", because the migration of free electrons from the interior of the plate to the surface is drastically affected by temperature. Steve "Eastburn" wrote in message ... I think the difference between real heavy plated batteries that would crank a car or truck for an hour to those of today that are both gel cell and thin plates. I had my truck battery replaced - it was a year old after all - and it was replaced with a thin plate junker. It often gives trouble if I don't drive over the weekend or it sits to long or multiple starts without a long charge run. These so called ENVIO batteries are not up to grade. Martin -- Martin Eastburn, Barbara Eastburn @ home at Lion's Lair with our computer NRA LOH, NRA Life NRA Second Amendment Task Force Charter Founder |
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O.T. Battery Charging
Hum - I have seen and heard many news accounts on these stupid models.
My understanding is the thin plates erode away and fall off in current capacity because of missing plate area. Part of the issue is the protection and general design. The battery people said it was a rush to market to limit lead in the public. We all know what that means. More batteries on the roads now from these, not excessive size plates returned in an exchange. The effect occurs on a hot or cold day. What GM doesn't understand is they run high current head lamps - all lamps during driving time and that limits battery charge current and the multi- processor designs all sucking power now. I don't think much thought was put into battery design lately since the High voltage battery is on the way to market. Yep - we are dumping 12V after all of these years. Martin -- Martin Eastburn, Barbara Eastburn @ home at Lion's Lair with our computer NRA LOH, NRA Life NRA Second Amendment Task Force Charter Founder |
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