Good batteries advice : Lead-Acid Batteries
What are variou types of Lead-Acid Batteries ?
SLA Sealed led-acid batteries
Small, sealed lead-acid (SLA) batteries are available to power portable devices.These batteries have capacities in the range 1.2–10Ah. However, due to their low energy density, they cannot be used in common applications, as computers and cellular phones, but in some applications that will be mentioned later.
These batteries have a limited amount of immobilized electrolyte. Their chemistry is the same as the common Pb-acid battery with excess electrolyte.SLA batteries can be made in cylindrical or prismatic configurations. For the latter, a thin version also exists.SLA cylindrical batteries can stand high currents also at low temperatures.
The main applications in portable devices can be summarized as:
- Portable TVs (use GP baterije)
- Measuring instruments
- Lighting equipment
- Various power toys and recreational equipment.
Batteries for Starting, Lighting, Ignition (SLI)
These batteries must possess the requisites of power density, energy density, cycle life, float service life and cost to a satisfactory level. Power is required to start an internal combustion engine (cranking).
As the engine runs, the battery is maintained on float, that is at full charge. To maximize the cranking ability, SLI batteries must have electrode grids with very low resistance, thin plates and concentrated acidic solutions.
The introduction of maintenance-free batteries has represented a major advance. They do not require H2O replenishment, have a better capacity retention and very low corrosion of the electrode terminals. Charge control is needed to avoid H2O loss. In contrast, as these batteries use low-Sb or Sb-free grids , the rate of H2O loss on overcharge is reduced.
Batteries of this type should be able to withstand long cycling, while featuring high energy density and low cost. These requisites overcome the performance of the present Pb-acid batteries, even in their advanced versions.
The technical challenges can be summarized as:
- greater specific energy
- higher specific power
- longer service life (at deep discharge)
- faster recharge time
A greater energy can be obtained by minimizing the weight of the inert components (normally 30%) and by improving the active material utilization.
Valve-regulated lead-acid batteries (VRLA, a term interchangeable with SLA) used in EV have specific energies of 30–40Wh/kg and energy densities of 80–90Wh/L .
How lead acid batteries ( akumulator baterija ) work
- Development of the Battery - Better Battery and ...
It is estimated that batteries have now been with man for more than 500 years. The earliest documented methods of generating electricity were by generating a static charge. It was not until the year 1800 that...
Most of these batteries are of the flooded-electrolyte type and are positive limited. High energy and power are not requested, but the capability of long living on float or moderate overcharge is necessary.
Overcharge causes expansion of the positive grid, and a 10% growth is allowed before the plates touch the container walls. Traditional batteries for telecommunication networks have lifetimes of 5–20 years.
To extend this life, a cylindrical battery has been built with circular, saucer-shaped pure Pb grids and horizontally stacked plates. Life was initially predicted to be 30 years or more. Data based on long-term corrosion investigations have allowed extending the life prediction to 68 years.VRLA batteries are now increasingly used, especially in telecom and UPS applications.
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