by GinoX » Mon Mar 14, 2011 8:04 am
Bo mes sa, kada bes tin un of otro discushon descabeya (pa no bisa otro palabra) over di bateria.....
>>>>>Begin Forwarded Information<<<<<
Information from "The Complete Battery Book" by Richard A. Perez.
Copyright 1985. ISBN 0-8306-0757-9
Four types of Lead-Acid batteries concern us for vehicular purposes,
automotive starting, low antimony deep-cycle, high antimony
deep-cycle, and gel-cells. I'll go over characteristics of each.
But first, a general note:
A) The storage capacity (ampere-hour rating) of a battery is a function
of the surface area of the plates exposed to the chemicals.
1) Automotive Starting Batteries
It has one job only: to start your car. An average car uses more than
300 amps for a few seconds in order to start. The batteries are
constructed with a large number of thin plates of lead sponge. This
provides maximum surface area. The batteries handle only very shallow
cycling, on the order of 1% in normal use. The starting battery will
fail after approx. 100 cycles of 50%. Complete failure at 200 cycles.
The sponge disintegrates with the repeated full charge and discharge
chemical reactions. Leat particles separate from the plates and from
micro-short circuits inside the battery. This highly increases the
self-discharge rate. Maintenence-free batteries have added calcium to
the lead sponges to harden them and reduce water loss. The calcium
also increases the internal resistance, hence slowing self-discharge.
The expected lifetime of a starting battery in true starting use is
3-5 years. In deep-cycle service, expect less than 2 years.
2) Low Antimony Deep Cycle Batteries
These are run-of-the-mill "marine/RV deep-cycle" batteries. It's a
compromise between a starting battery and a true deep-cycle battery.
They are much closer to starting batteres, however. The plates are
somewhat thicker than starting batteries and have some added antimony.
It is not designed for powering large loads for a long time.
Deep-cycling will damage it, over time. In RV use, with usually no
more than 20% discharge, the battery should last 200-400 cycles. If
cycled 80%, expect a lifetime of less than 200 cycles, or about the
same as the starting battery. The thicker plates and antimony add a
bit of mechanical strength over the standard starting battery. In
float service, the battery will last 5-10 years, much greater than
starting batteries used in float service.
3) High Antimony Deep Cycle Batteries
This type is designed to be 80% cycled repeatedly for 5-15 years.
There is almost no mechanical similarity between this battery and a
starting battery. They are massive and huge. There are very few true
deep cycle batteries with greater than 6 volts, as they would be too
heavy to move by hand. The grids are over 4 times thicker than a
starting battery's grids. And there is several times the amount of
antimony in the grids. The plates are thick to add lifetime, not
capacity. (See A). The plates are not constructed of sponge, but of
scored sheets of lead with up to 16% antimony. The thickness of the
plates combined with the high antimony content lowers the energy
density, so this battery is heavier, larger and much more costly per
kilowatt-hour. The case is also much thicker, and the plates usually
leave a 1-3 inch space at the bottom to allow for accumulation of lead
particles, so that they don't cause micro-shorts. The top of the case
also has more space to allow for expansion of the electrolyte. Plates
can be removed and serviced. As the cell interconnect straps are
exposed, each cell's voltage can be measured individually. This
allows the user to determine when an equalizing charge is necessary.
Some batteries have "wrapped" plates, where perforated plastic is
wrapped around the plates to keep the lead on them longer. Such a
configuration add 25-35% to the lifetime of the battery. Such
batteries are mostly used for electric vehicles, which force a fast
80% or more discharge. They are then recharge much more slowly. A
350 amp-hr 12 volt battery weight 250 pounds and contains 4.5 gallons
of sulphuric acid. They can be cycled 80% between 1000 and 2000
times. Lifetime should be 5-15 years.
4) Gel Cells
This type is designed for portability. They are small and have a
jellied electrolyte. The case is sealed. The jellied electrolyte
allows the use of this battery in any orientation. They are used
often in aircraft and electronics. They are supposed to be clean and
usuable where acid vapors and spills are unacceptable. They can be
deep-cycled over long periods. They must not be charged or discharged
too rapidly, otherwise it can gas, possibly blowing the sealed case.
They are prone to sulfation if left discharged for a long time. With
proper care, a gel-cell will deliver 1000 cycles over a period of 5
years or more.
============
Bo mes sa, kada bes tin un of otro discushon descabeya (pa no bisa otro palabra) over di bateria.....
>>>>>Begin Forwarded Information<<<<<
Information from "The Complete Battery Book" by Richard A. Perez.
Copyright 1985. ISBN 0-8306-0757-9
Four types of Lead-Acid batteries concern us for vehicular purposes,
automotive starting, low antimony deep-cycle, high antimony
deep-cycle, and gel-cells. I'll go over characteristics of each.
But first, a general note:
A) The storage capacity (ampere-hour rating) of a battery is a function
of the surface area of the plates exposed to the chemicals.
1) Automotive Starting Batteries
It has one job only: to start your car. An average car uses more than
300 amps for a few seconds in order to start. The batteries are
constructed with a large number of thin plates of lead sponge. This
provides maximum surface area. The batteries handle only very shallow
cycling, on the order of 1% in normal use. The starting battery will
fail after approx. 100 cycles of 50%. Complete failure at 200 cycles.
The sponge disintegrates with the repeated full charge and discharge
chemical reactions. Leat particles separate from the plates and from
micro-short circuits inside the battery. This highly increases the
self-discharge rate. Maintenence-free batteries have added calcium to
the lead sponges to harden them and reduce water loss. The calcium
also increases the internal resistance, hence slowing self-discharge.
The expected lifetime of a starting battery in true starting use is
3-5 years. In deep-cycle service, expect less than 2 years.
2) Low Antimony Deep Cycle Batteries
These are run-of-the-mill "marine/RV deep-cycle" batteries. It's a
compromise between a starting battery and a true deep-cycle battery.
They are much closer to starting batteres, however. The plates are
somewhat thicker than starting batteries and have some added antimony.
It is not designed for powering large loads for a long time.
Deep-cycling will damage it, over time. In RV use, with usually no
more than 20% discharge, the battery should last 200-400 cycles. If
cycled 80%, expect a lifetime of less than 200 cycles, or about the
same as the starting battery. The thicker plates and antimony add a
bit of mechanical strength over the standard starting battery. In
float service, the battery will last 5-10 years, much greater than
starting batteries used in float service.
3) High Antimony Deep Cycle Batteries
This type is designed to be 80% cycled repeatedly for 5-15 years.
There is almost no mechanical similarity between this battery and a
starting battery. They are massive and huge. There are very few true
deep cycle batteries with greater than 6 volts, as they would be too
heavy to move by hand. The grids are over 4 times thicker than a
starting battery's grids. And there is several times the amount of
antimony in the grids. The plates are thick to add lifetime, not
capacity. (See A). The plates are not constructed of sponge, but of
scored sheets of lead with up to 16% antimony. The thickness of the
plates combined with the high antimony content lowers the energy
density, so this battery is heavier, larger and much more costly per
kilowatt-hour. The case is also much thicker, and the plates usually
leave a 1-3 inch space at the bottom to allow for accumulation of lead
particles, so that they don't cause micro-shorts. The top of the case
also has more space to allow for expansion of the electrolyte. Plates
can be removed and serviced. As the cell interconnect straps are
exposed, each cell's voltage can be measured individually. This
allows the user to determine when an equalizing charge is necessary.
Some batteries have "wrapped" plates, where perforated plastic is
wrapped around the plates to keep the lead on them longer. Such a
configuration add 25-35% to the lifetime of the battery. Such
batteries are mostly used for electric vehicles, which force a fast
80% or more discharge. They are then recharge much more slowly. A
350 amp-hr 12 volt battery weight 250 pounds and contains 4.5 gallons
of sulphuric acid. They can be cycled 80% between 1000 and 2000
times. Lifetime should be 5-15 years.
4) Gel Cells
This type is designed for portability. They are small and have a
jellied electrolyte. The case is sealed. The jellied electrolyte
allows the use of this battery in any orientation. They are used
often in aircraft and electronics. They are supposed to be clean and
usuable where acid vapors and spills are unacceptable. They can be
deep-cycled over long periods. They must not be charged or discharged
too rapidly, otherwise it can gas, possibly blowing the sealed case.
They are prone to sulfation if left discharged for a long time. With
proper care, a gel-cell will deliver 1000 cycles over a period of 5
years or more.
============
