SMA Sunny Island 2012 Technical Description page 204

SMA Solar Technology AG
Glossary
Boost Charge
Quick charge: allows the battery to be charged to a level of approx. 85 – 90 % as quickly and
efficiently as possible.
Bulk Phase
I-Phase: the charging phase in which charging can be performed using the maximum charging
current.
Capacity
Describes the storage capability of a cell or battery, specified in Ah (ampere hours). The capacity
of a battery is heavily dependent on the charging cycle, the amount of current drawn and the
temperature.
Central inverter
An inverter concept in which all PV modules are connected to each other (in series and/or parallel)
and which uses a single inverter for feeding energy into the external grid. The lower cost of the
inverter is usually offset by the much higher installation outlay required and possible yield losses due
to variations in shadowing on individual solar modules.
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 within
a cluster must be connected via a communication cable and configured in a way 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 V is reached. For permanently on-site batteries, the C
S 10
capacity is usually specified. I. e. a battery with C = 200 Ah can be discharged for 10 hours at
10
a nominal current of 0.1 × C = I = 20 A.
10 10
DC
Abbreviation for "Direct Current".
204 SI2012_2224-TEN082311 Technical Description