Page 89
©
2017 Sensata Technologies
Appendix C – Terminology
Appendix C – Charge Controller Terminology
The following is a glossary of terms with which you may not be familiar. They appear in the
various descriptions of charge controller and battery charger operation.
Absorption Stage
– In this second stage of three stage charging, the batteries are held at a
constant voltage (the absorb voltage setting) and the battery is charged to its maximum capacity.
Ampacity
– The ampacity of a wire is its current carrying capacity with reference to the cross-
sectional area of the conductors, the temperature rating of the insulation and the ambient
temperature.
Bulk Charge Stage
– The
fi
rst stage in three-stage charging. In this stage, a constant current is
fed to the batteries and as they accept the current the battery voltage will rise.
CEC
(Canadian Electrical Code)
– The guidelines and acceptable practices for electrical
installations in Canada.
Current (Amps)
– The amount of electricity
fl
owing through a conductor.
DC (Direct Current)
– Electrical current that does not vary with time (i.e., battery voltage).
Deep Cycle
– A deep cycle occurs when a battery is discharged to less than 20% of its capacity
(80% depth-of-discharge).
Derating
– As a charge controller (or charger) is used above its normal temperature, its capacity
to charge continuously is decreased.
Effi ciency
– Usually given as a percentage, ef
fi
ciency is the ratio of the output to the input. The
ef
fi
ciency changes with power output levels of any charge controller.
Electrolyte
– Typically a mixture of water and sulfuric acid that is used in lead-acid batteries; it
is commonly referred to as battery acid.
Equalization
– Controlled “overcharging” of the battery causing it to bubble and mix. This helps
reduce strati
fi
cation.
Float Stage
– During the third stage of three-stage charging, the voltage and current are reduced
to a level that will trickle charge or maintenance charge the battery. This assures the battery
remains fully charged even while sitting.
Fuse or Disconnect
– When current exceeds a preset limit, the fuse or disconnect will fail before
the wiring or equipment it is protecting. Disconnects are also called circuit breakers. These are
usually reset, and can act as a switch to turn off power to equipment for servicing.
LED (Light Emitting Diode)
– A light made up of semi-conducting material.
Load(s)
– An electrical item that draws power (e.g., lights, radio, refrigerator, etc.,) to work.
NEC (National Electric Code)
– The guidelines and acceptable practices for electrical installations
in the USA.
Photovoltaic (PV)
– Solar powered.
Resistance
(Ohms)
– Slows the electrical
fl
ow of direct current (DC).
Stacking (PT-100’s) -
Multiple charge controllers operating together to charge and regulate the
battery voltage.
Stratifi cation
– Over time, a battery’s electrolyte (liquid) tends to separate. The electrolyte at
the top of the battery becomes watery, while at the bottom it becomes more acidic.
Sulfating
– As a battery discharges, its plates become covered with lead sulfate. During
recharging, the lead sulfate leaves the plates and recombines with the electrolyte. If the lead
sulfate remains on the plates for an extended period of time (over two months), it hardens, and
recharging will not remove it. This reduces the effective plate area and the battery’s capacity.
Temperature Compensation
– Peak available battery voltage is temperature dependent. A
Battery Temperature Sensor (BTS) automatically re-scales charge voltage settings to compensate
for ambient temperatures.
Voltage
– The pressure that causes electrical
fl
ow in a circuit.
Watts
– Measure of power output or utilization. Watts = Volts x Amps.
