10-05-2006, 12:45 PM
seal sees on plii , aga need restid , mille sees see plii on , mis materjalist need on ?v6i on hoopis restid pliist ja see möga mis restide sees on siis mingi muu möga?
10-05-2006, 12:45 PM
10-05-2006, 12:56 PM
10-05-2006, 13:28 PM
Et oleks puust ja punaseks nagu Tootsi maakera, postitan siia ühe õpetliku ja hariva FAQ materjalid 
Lead secondary cells
The so-called lead-acid secondary battery has long been the most widely used rechargeable portable power source. Most such batteries are constructed of lead plates, or grids, where one of the grids, the positive electrode, is coated with lead dioxide in a particular crystalline form, along with additives such as calcium lignosulfate. The electrolyte, composed of sulfuric acid, participates in the electrode reactions where lead sulfate is formed and carries current in moving ions. Recent estimates show that in terms of capacity in use (watt-hours), the lead-acid battery has 20 times as much capacity as either the nickel–cadmium or nickel–iron alkaline rechargeable battery.
The lead-acid battery system has been as successful as it has because of the following features: wide capability range for high or low current demand over usual ambient temperatures; good cycle life with high reliability for hundreds of cycles, especially with good recharge control (a gram of positive active material may deliver as many as 100 ampere-hours during the service life of such a battery); relative low cost (lead is less expensive per kilogram or per ampere-hour than nickel, cadmium, or silver); comparatively good shelf life for a rechargeable system when stored; high cell voltage at 2.04 volts per cell; ease of fabricating lead components by casting, welding, or rolling; and a high degree of salvageability at low melting temperatures.
An area of continued interest for investigators working on lead-acid batteries is reduction of battery weight. Lead dioxide and lead have the lowest energy density of the major electrode materials in wide use, and they are rarely discharged in a highly efficient manner. At low rates of discharge, only about 60 percent of the active materials are cycled, and on short, 10-minute heavy loads utilization can fall to 10 percent.
Lead-acid batteries are generally classified into three groups: (1) starting–lighting–ignition (SLI) batteries, (2) traction batteries, and (3) stationary batteries. The automotive SLI battery is the best-known portable rechargeable power source. High current can be obtained for hundreds of shallow-depth discharges over a period of several years. Traction batteries are employed in industrial lift trucks, delivery trucks, and other vehicles. While some are readily portable, others may weigh several tons. The great weight often serves to stabilise the vehicle during operation. Stationary batteries are now much more common than was once the case. These batteries have heavier grid structures and other features to give them long shelf life. They are used to power emergency lights and in uninterruptible power systems for hospitals, factories, and telephone exchanges.
In a lead-acid battery the active material of the positive electrode, lead dioxide, combines with the electrolyte, sulphuric acid, to produce lead sulphate and water during discharge. At the negative electrode the constituent lead combines with the sulphuric acid ions to produce lead sulphate and hydrogen ions, thereby replacing the hydrogen ions consumed at the positive electrode. The water formed and the loss of sulfate dilutes the electrolyte, lowering its density. Due to this, the state of charge of a lead-acid battery can be determined from the specific gravity of the electrolyte.
Lead secondary cells
The so-called lead-acid secondary battery has long been the most widely used rechargeable portable power source. Most such batteries are constructed of lead plates, or grids, where one of the grids, the positive electrode, is coated with lead dioxide in a particular crystalline form, along with additives such as calcium lignosulfate. The electrolyte, composed of sulfuric acid, participates in the electrode reactions where lead sulfate is formed and carries current in moving ions. Recent estimates show that in terms of capacity in use (watt-hours), the lead-acid battery has 20 times as much capacity as either the nickel–cadmium or nickel–iron alkaline rechargeable battery.
The lead-acid battery system has been as successful as it has because of the following features: wide capability range for high or low current demand over usual ambient temperatures; good cycle life with high reliability for hundreds of cycles, especially with good recharge control (a gram of positive active material may deliver as many as 100 ampere-hours during the service life of such a battery); relative low cost (lead is less expensive per kilogram or per ampere-hour than nickel, cadmium, or silver); comparatively good shelf life for a rechargeable system when stored; high cell voltage at 2.04 volts per cell; ease of fabricating lead components by casting, welding, or rolling; and a high degree of salvageability at low melting temperatures.
An area of continued interest for investigators working on lead-acid batteries is reduction of battery weight. Lead dioxide and lead have the lowest energy density of the major electrode materials in wide use, and they are rarely discharged in a highly efficient manner. At low rates of discharge, only about 60 percent of the active materials are cycled, and on short, 10-minute heavy loads utilization can fall to 10 percent.
Lead-acid batteries are generally classified into three groups: (1) starting–lighting–ignition (SLI) batteries, (2) traction batteries, and (3) stationary batteries. The automotive SLI battery is the best-known portable rechargeable power source. High current can be obtained for hundreds of shallow-depth discharges over a period of several years. Traction batteries are employed in industrial lift trucks, delivery trucks, and other vehicles. While some are readily portable, others may weigh several tons. The great weight often serves to stabilise the vehicle during operation. Stationary batteries are now much more common than was once the case. These batteries have heavier grid structures and other features to give them long shelf life. They are used to power emergency lights and in uninterruptible power systems for hospitals, factories, and telephone exchanges.
In a lead-acid battery the active material of the positive electrode, lead dioxide, combines with the electrolyte, sulphuric acid, to produce lead sulphate and water during discharge. At the negative electrode the constituent lead combines with the sulphuric acid ions to produce lead sulphate and hydrogen ions, thereby replacing the hydrogen ions consumed at the positive electrode. The water formed and the loss of sulfate dilutes the electrolyte, lowering its density. Due to this, the state of charge of a lead-acid battery can be determined from the specific gravity of the electrolyte.
10-05-2006, 17:12 PM
10-05-2006, 17:28 PM
KILLER666 Kirjutas:restidena pidasin silmas neid millest see plaat koosneb.... mis materjalist need restid on mille sisse plii ja pliioxiid pandud
on?
Seda ma täpselt ei tea. Aga need plaatide tugikonstruktsioonid akukeemias mingit rolli ka ei mängi - peaasi, et nad tööorgani ehk aktiivse poorse aine paigal ning ühes tükis hoiavad ning ei tekita mingit omapoolset segavat lisareaktsiooni akus. Nii et tee need kasvõi kullast, nagu üks teatud poliitiline liikumine kunagi s...potte kavatses tegema hakata
(Kuld teatavasti on väga loid keemilistesse reaktsioonidesse astuma.)Tõenäoliselt on vast need tugikonstruktsioonid ise ka miskist pliist või pliisulamist. Vähemalt on vanu akusid lammutades mul selline tunne jäänud.
10-05-2006, 17:57 PM