SMA SI 3324 - Manual (Page 67)

SMA Technologie AG Glossary
User Manual SI3324/4248-14:FE2406 Page 153
21 Glossary
Absorption phase
Constant Voltage phase: A charging phase using constant charging voltage. The
charging current constantly decreases in this phase.
AC
Abbreviation for "Alternating Current"
AC coupling
The AC side connection between loads, generators and storage devices.
AGM battery
Absorbent Glass Mat separator battery. This is a battery where the electrolyte (a
mixture of water and sulfuric acid) is bound to a glass fiber mat. This is a type of a
sealed lead acid battery. A gas mixture (hydrogen and oxygen) is always generated
when lead-acid batteries are charged and in normal operation this internally
recombines to form water. This removes the need for regularly refilling the battery
cells with water, which is why these batteries are often described as "low
maintenance" or even "maintenance free". AGM batteries are available from many
different manufacturers for a wide range of applications. They usually have very
good high current properties but are not very charge-cycle resistant.
Ah
Abbreviation for "Ampere hours". Unit of electrical charge, one ampere hour is the
charge provided by a constant current of 1 A over a period of one hour.
Backup system
Backup systems are power supply systems that provide an extra level of security for
standard power supply systems. The public grid is usually the standard power supply
system and the backup system is provided by an additional stand-alone grid in the
case of a power outage. In addition to the backup systems, diesel generators in PV
battery systems are also described as backup generators. Here they perform the
same task as a backup system for the public grid.
Battery
A battery is an electrochemical storage device that can release previously stored
chemical energy as electrical energy. A distinction is made between non-
rechargeable primary elements (often used in consumer markets) and rechargeable
secondary elements (accumulators). In stand-alone grid systems, lead acid batteries
are almost always used and, very rarely, Nickel/Cadmium batteries are used as
secondary rechargeable elements.
Battery bank
See Battery system