Genasun

Glossary

Absorption Voltage: For lead-acid batteries (including Gel-cell and AGM batteries): a higher voltage than float voltage used in a stage of Multi-Stage Charging when the battery is nearly full. Charging to this higher voltage reduces sulfation on the electrode plates in the battery, so may extend the battery's usable life. After the absorption voltage stage, the battery is typically held at the float voltage
Acceptance Charge: A name for a constant-voltage stage of battery charging during which the battery is held at the absorption voltage.
AGM: Absorbent Glass Mat (or Absorbed Glass Mat): A type of lead-acid battery in which the electrolyte is held in separators made of a mat of glass fibers. Both AGM and Gel-cell batteries are types of valve-regulated lead-acid batteries (sometimes also called sealed lead-acid batteries).
Amp-Hours: Unit of battery capacity. The number of hours a constant-current discharge could continue, multiplied by the discharge current, in Amps.
Because this number varies with discharge rate, either the duration of the discharge (typically 20 hours for lead-acid battery specifications) or the discharge rate should be given.
Ampere: A unit of current, usually abbreviated as "Amp." One Amp of current means that one Coulomb (a unit of electrical charge) flows past a point in one second. In the common analogy between electricity and water, electrical current is analogous to the flow rate.
Amps per Hour: Most often seen as a misnomer when the user meant "Amps." A similar misnomer is to use "Amps" referring to battery capacity: usually the number given is the correct battery capacity in Amp-Hours.
Balance: "For battery packs: Loosely, the degree to which cells in a pack are at the same state of charge. Balancing is crucially important for lithium-ion batteries and can be important for high-voltage lead-acid battery packs. "
Battery: An electrochemical device which stores energy. Common types today include lead-acid, lithium-ion, nickel-cadmium, and nickel-metal hydride. Also used to refer to a battery pack.
Battery Cell: An electrochemical cell consisting of anode, cathode, and electrolyte, which can store energy chemically and release it as electricity. The voltage of a battery cell is uniquely determined by the specific chemicals used.
Battery Efficiency: Portion of the energy required to fully-charge a fully-discharged battery that is available for the next discharge. Typical efficiency for a lead-acid battery is in the mid-70 to upper-80 percent range. For a lithium-ion battery, the efficiency may reach the upper 90's.
Measured as: (Available discharge energy) / (energy used in charging)
Battery management: In battery packs, everything necessary to operate individual battery cells safely. At Genasun, this includes balancing of cells, protection against overcharge and overdischarge, protection against temperatures outside the battery cells' safe operating temperatures, etc.
Battery Pack: Assembly of battery cells connected to achieve a desired capacity and / or voltage, usually also including the mechanical support and electrical management necessary for operation.
Bulk Charge: Stage of battery charging during which charge current is at the charger's or the battery pack's current limit and battery voltage rises as the battery charge increases. May also be called Constant-Current Charge.
Cell: See Battery Cell or Solar Cell.
Charge Controller: Electronic module that controls the power from some energy source to charge a battery. Charge controllers are commonly used with energy sources including solar panels, wind generators, fuel cells, micro-hydro power.
Constant-Current Charge: The first stage of battery charging, when charge current is at the charger's current limit and battery voltage rises as the battery charge increases. May also be called Bulk Charge.
Constant-Voltage Charge: A stage of battery charging during which the battery voltage is held constant.
Efficiency: In general, power produced divided by some theoretical measure of power available. See Panel Efficiency, Electrical Efficiency, Battery Efficiency, or Tracking Efficiency.
Electrical Efficiency: Conversion efficiency of the power electronics: (Power out) / (Power in)
Float Voltage: The voltage at which a charger holds a fully-charge battery is held to prevent self-discharge. Also, the final stage of multi-stage charging.
Gel-Cell: A type of lead-acid battery in which the electrolyte is a gel rather than a liquid. Both AGM and gel-cells are types of valve-regulated lead-acid batteries (sometimes also called sealed lead-acid batteries).
Insolation: The amount of sunlight incident on a surface, often measured in Watts per square meter. See also Standard Insolation.
Lead-Acid: A type of battery which uses lead plates as electrodes and sulphuric acid as the electrolyte. Lead-acid batteries have been used longer than other rechargeable battery types in use today, and are notable for being fairly cheap and heavier than other sorts of batteries. Almost all 12V automotive batteries, for example, are lead-acid. AGM and gel-cell batteries are types of lead-acid batteries.
Lithium-Ion Battery: A type of battery which uses lithium-based compounds for an electrode. Types of lithium-ion batteries commonly used today include lithium-cobalt-oxide, lithium-manganese, and lithium-iron-phosphate.
Lithium-Polymer: A type of battery chemically nearly equivalent to lithium-ion batteries, with a gelled electrolyte. "Lithium-ion" is sometimes used to refer only to those lithium-ion batteries with a liquid electrolyte, and sometimes to refer to all those with liquid or gelled electrolytes.
Load: In electronics: a consumer of electrical power. For solar charge controllers, this is typically a charging battery and whatever equipment is powered by the battery.
Low light: Light condition in which significantly less light than standard insolation is available.
Maximum Power Point: The electrical operating point of a solar panel or other energy-collecting device at which more power is produced than any other available operating point. For a solar panel, equivalent to Maximum Power Voltage.
Maximum Power Point Tracking: Any technique to operate an energy-collecting device at its Maximum Power Point.
Maximum Power Voltage: The operating voltage of a solar panel at which more power is produced than any other available operating point. For a solar panel, equivalent to Maximum Power Point.
MPPT: Maximum Power Point Tracking.
Multi-Stage Charging: Battery charging method that includes multiple stages. Usually, the stages include a current-limited stage that lasts until the battery voltage rises to some voltage threshhold, an absorption stage that lasts for some fixed amount of time, and a voltage-limited trickle-charge stage that continues indefinitely.
Night Consumption: For solar charge controllers, the power taken by the controller when there is no power supplied by the solar panel.
Operating Consumption: For solar charge controllers, the power taken by the controller itself while the controller is charging the battery.
Panel Efficiency: The efficiency of a solar panel: quoted as the power produced at the Maximum Power Voltage under standard insolation, divided by the standard insolation power of 1000 Watts per square meter.
Partial Shading: Light condition in which light is blocked from reaching some cells of a solar panel but not others.
PWM (in power electronics context): Puse Width Modulation. A signal varies rapidly between two extremes, and the output signal level is understood to be the average of the two, weighted by the percent of time the signal is at each of the extremes. (The time average, found by using a low-pass filter.)
PWM (in solar-charge controller context): A method of limiting current when the battery is fully charged by turning the full charge current on and off.
Sealed Lead-Acid Battery: A type of lead-acid battery that does not require the user to add water, but has a valve to release any gases that may, on rare occasions develop. Both AGM and Gel-cells are types of valve-regulated lead-acid batteries (sometimes also called sealed lead-acid batteries).
Equivalent to Valve-Regulated Lead-Acid Battery.
Self-Consumption: For solar charge controllers: used to mean either Operating Consumption or Night Consumption.
Self-Discharge: A battery's natural loss of charge over time. Self-discharge is often specified as percent loss of capacity per month. Lithium batteries' self-discharge is considered to be fairly low, at a few percent per month. NiCads have higher self-discharge, and lead-acid batteries' self discharge is somewhere in the middle.
SLA: Sealed Lead-Acid Battery. Equivalent to Valve-Regulated Lead-Acid Battery.
Solar Cell: A material that produces electrical current in the presence of light. Solar cells are usually made of silicon, are typically several inches on a side and very thin, and are a building block of solar panels.
Solar Charge Controller: Electronic module that controls the power from a solar panel to charge a battery. See also Charge Controller.
Solar Panel: A device which produces electricity from light, usually consisting of many solar cells, mechanical support, and electrical wiring.
Standard Insolation: Insolation considered typical on a sunny day when the sun's rays shine through a clear atmosphere and perpendicular to the Earth's surface (e.g. at noon on the equator on the equinox): Defined as 1000 W of sunlight per square meter of panel. Solar panel power ratings are almost always the power they would produce in these conditions when operating at a temperature of 25 degrees Celsius and at the Maximum Power Voltage.
Tracking Efficiency: Degree to which a charge controller accurately tracks the maximum power point. A controller with true Maximum Power Point Tracking will achieve tracking efficienies of near 100 percent in all conditions, while PWM controllers' tracking efficiencies will generally be 70 to 90%.
Measured as (Power out) / (Power out possible at Maximum Power Point).
Trickle-Charge: A continuous low-current charge used to keep nickel-cadmium batteries at their full capacity. Analogous to charging a lead-acid battery at the float voltage.
Valve-Regulated Lead-Acid Battery: A type of lead-acid battery that does not require the user to add water, but has a valve to release any gases that may develop on rare occasions. Both AGM and gel-cells are types of valve-regulated lead-acid batteries (sometimes also called sealed lead-acid batteries).
Equivalent to Sealed Lead-Acid Battery.
Volts: Unit of voltage. In the analogy between electricity flowing in channels and water, voltage corresponds to the height of the water.
VRLA: Valve-Regulated Lead-Acid Battery. Equivalent to Sealed Lead-Acid Battery.
Watts: Unit of power. One Watt is equal to one Volt multiplied by one Amp.