SunXtender Technical Manual
Table Of Contents
Document No. 6-0100 Rev. H   
Page 31 of 43 
Migration - 
Directed movement of an ion of the electrolyte under the influence 
of an electric field. 
Monobloc - 
A battery assembly that contains multiple cells connected in series 
or parallel and housed in a single container.  
Negative Electrode - 
See Negative Plate. 
Negative Plate - 
The plate which has an electrical potential below that of the other 
plate during normal cell operation. Positive current flows to the 
negative plate during discharge. 
Nominal Voltage - 
Equivalent to the number of cells in series in a battery times 2 
volts per cell. A 6-cell battery has a nominal voltage of 12 volts.  
Open Circuit Voltage - 
The voltage of a battery when it is not delivering or receiving 
power, and has been at rest long enough to reach a steady state 
(normally, at least 4 hours). 
Overcharge - 
The forcing of current through a cell after all the active material 
has been converted to the 
charged state. In other words, charging 
continued after 100% state of charge is achieved. The result will 
be the decomposition of water in the electrolyte into hydrogen and 
oxygen gas, heat generation, and corrosion of the positive 
electrode. 
Oxygen recombination - 
The process by which oxygen generated at the positive plate 
during charge reacts with the pure lead material of the negative 
plate and in the presence of sulfuric acid reforms water. 
Parallel connection - 
Voltage stays the same, discharge rate and AH capacity are 
additive. 
Plate - 
A grid or framework that gives mechanical support to the active 
materials of a cell. The combination is termed a pasted plate. 
Polarity - 
The electrical term used to denote the voltage relationship to a 
reference potential (+). 
Positive Electrode - 
See Positive Plate. 
Positive Plate - 
The plate which has an electrical potential higher than that of the 
other plate during normal cell operation. Positive current flows 
from the positive plate during discharge. 
Power - 
Rate at which energy is released or consumed (expressed in 
watts). 
Power Efficiency - 
The proportion, expressed in percent, of energy recovered from a 
storage system, i.e: output power divided by input power. 
Rated Capacity - 
See Capacity, Rated 
Rechargeable Secondary 
Cell or Battery - 
A cell or battery which can be recharged many times after being 
discharged without appreciable depreciation of capacity. 
Recombination - 
See Oxygen recombination. 
Resealable Vent Valve- 
A type of pressure relief valve which is capable of closing after 
each pressure release, in contrast to a non-resealable vent valve. 
Reversible Reaction - 
A chemical change which takes place in either direction, as in the 
reversible reaction for charging or discharging a secondary 
battery. 
Sealed Cells - 
Cells that contain a resealable vent valve and do not require 
electrolyte maintenance. 
Secondary Battery - 
A system which is capable of repeated use by employing chemical 
reactions that are reversible, i.e., the discharged energy may be 
restored by supplying electrical current to recharge the cell. 
Self Discharge - 
The decrease in the state of charge of a cell or a battery, over a 
period of time, due to internal electrochemical losses. 
Separator - 
An insulating sheet or other device employed in a storage battery 
to prevent metallic contact between plates of opposite polarity 
within a cell. 










