SunXtender Technical Manual

Document No. 6-0100 Rev. H
Page 30 of 43
End Of Life -
The stage at which the battery fails to deliver acceptable capacity
(typically 50% of nameplate rating).
End Point Voltage -
Voltage at which point the rated discharge capacity had been
delivered at a specified rate of discharge. Also used to specify
voltage below which the connected equipment will not operate or
below which operation is not recommended. Sometimes called
cutoff voltage or voltage end point.
Energy -
Output capability, expressed as capacity times voltage, or
Watt hours (Whr).
Energy Conversion -
The change from chemical to electrical energy within the cell, or
the reverse.
Energy Density -
The ratio of battery energy to either the weight (Wh/lb or Wh/kg)
or the volume (Wh/L or Wh/cu.in.).
Environmental Conditions -
External circumstances to which a cell or battery may be
subjected, such as ambient temperature, humidity, shock, and
vibration.
Equalization Charge -
A maintenance procedure consisting of a sustained overcharge
used to correct cell imbalance.
Fast charging -
Rapid return of energy to a battery at the C rate or higher.
Float charge -
A method of maintaining a battery in a charged condition by
continuous, long
term, constant voltage charging at level sufficient
to balance self-discharge.
Flooded cell -
A cell design which incorporates an excess amount of electrolyte,
also see Vented Cell.
Gassing -
The evolution of gas from one or more of the electrode plates in a
cell. Gassing commonly results from local action (self-discharge)
or from the electrolysis of water in the electrolyte during charging.
High Rate Discharge -
Withdrawal of large amounts of current for short intervals of time
from a battery, usually at a rate that will completely discharge a
cell or battery in less than 1 hour.
Internal Impedance -
Same as Internal Resistance.
Internal Resistance -
The opposition or resistance to the flow of a direct electric current
within a cell or battery; the sum of the ionic and electronic
resistance of the cell components. Its value varies with the
current, state of
charge, temperature, and age. With an extremely
heavy load, such as an engine starter, the cell voltage may drop
significantly. This voltage drop is due to the internal resistance of
the cell. A cell that is partly discharged has a higher internal
resistance than a fully charged cell, hence it will have a greater
voltage drop under the same load. This change in internal
resistance is due to the accumulation of lead sulfate in the plates.
Ion -
Part of a molecule or group of atoms, positively or negatively
charged, which transports electricity through the electrolyte.
Lead Acid -
Terms used in conjunction with a battery that utilizes lead and
lead dioxide as the active plate materials in a diluted electrolyte
solution of sulfuric acid and water.
Lead Dioxide -
A higher oxide of lead present in charged positive plates and
frequently referred to as lead peroxide (PbO
2
).
Lead Sulfate -
A lead salt formed by the action of sulfuric acid on lead oxide
during paste mixing and formation. It is also formed
electrochemically when a battery is discharged.
Life -
The duration of satisfactory performance, measured as usage in
years or as the number of charge/discharge cycles.
Low Rate Discharge -
Withdrawal of small amounts of current for long periods of time
from a battery.