SMA S Technical Description page 172

Glossary SMA Solar Technology AG
Charge Level
Describes the present amount of charge which can be drawn from the battery, in percent of the
nominal capacity (100 % = battery full, 0 % = battery empty).
Charge Mode
See Battery Charging Mode.
Charging Throughput
See Nominal Charging Throughput.
Cluster
Several Sunny Island or Sunny Backup inverters which are connected in parallel on the DC side, and
which are connected to a shared battery system. On the AC output side, these inverters can also be
connected in parallel (single-phase system), or form a multi-phase system. The devices in a cluster must
be connected by communication cables, and must be configured in such a manner that one device
(-> master) leads the cluster, and all other devices (-> slaves) communicate with the leading device.
C Rate
The nominal capacity specification is always provided along with the discharge time on which the
capacity is based. The nominal capacity is the product of the constant charging current I and the
N
discharge time t , which passes between commencement of discharging the fully charged battery
N
and when the final discharge voltage U is reached. For stationary batteries, the C capacity is
S 10
usually specified, i.e. a battery with C = 200 Ah can be discharged for 10 hours at a nominal
10
current of 0.1 × C = I = 20 A.
10 10
DC
Abbreviation for "Direct Current"
Derating
English for "reduction": a controlled reduction in performance, usually dependent on component
temperatures. Compared with the (also common) practice of completely shutting down the device, the
effect on the grid is smaller with derating.
DSP
Abbreviation for Digital Signal Processor. A DSP is a microprocessor chip especially developed for
digital signal processing and control.
Electrolyte
Allows the conduction of ions within a battery. In a lead acid battery, the electrolyte is diluted sulfuric
acid and is also a reactant in the electrochemical reaction. Nickel/cadmium batteries use an alkaline
electrolyte (potassium hydroxide).
EPROM
See Flash EEPROM.
Equalization Charge
See Equalize Charge
172 SBU2200-TEN083320 Technical Description