SMA SIC 50 - Manual (Page 23)

SMA Solar Technology AG Electrical Connection
Installation Guide SIC50-IA-en-11 23
6.5 Battery Connection (DC)
Connection Requirements
• Observe all standards and guidelines that apply at the installation location (e.g. DIN VDE 0510
"Rules for Accumulators and Battery Systems").
• Observe all specifications of the battery manufacturer.
Cable Requirements
Cable Protection
In addition to the thermal fuses in the charge controller, install a separate fuse as close to the battery
as possible. Install a suitable fuse according to the maximum specified DC currents. You can, for
example, install a 63 A miniature circuit breaker.
Battery capacity
The battery capacity depends on the connected PV power.
Observe the following table.
Nominal battery voltage Battery capacity per kWp PV
48 V at least 120 Ah/kWp PV
24 V at least 200 Ah/kWp PV
12 V at least 400 Ah/kWp PV
Excessively long battery cables reduce system efficiency
The cables leading from the battery to a DC distributor to which both the Sunny Island and
the charge controller are connected may not be longer than 5 m.
NOTICE!
Irreparable damage of the cable leading from the charge controller to the
battery.
• Do not lay the battery cables under plaster or in armored plastic pipes.
NOTICE!
Irreparable damage of the cable leading from the charge controller to the
battery.
• Lay the battery cables so that they are protected against ground faults and short
circuits if no line circuit breaker is present.
• Make sure that the cable cross-section is sufficient.