Instructions / Assembly

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10
Common Questions
How many batteries will I need to go with my panels?
Batteries have to do with how much power storage your system needs regardless of how much generation
capacity you have. You can have 10kW of solar panels charging a 36Ah battery or you could have one
100W panel charging 1200Ah of batteries. The panel just affects how quickly the battery can be charged.
If the battery bank is fully charged the charge controller will prevent over charging.
What inverters will work with my panels?
In an off-grid, battery backup system, the inverter is connected to a battery bank and the panels feed
power onto the battery bank through a charge controller. Since the inverter isn’t directly connected to the
panels, you can use any size inverter you want as long as it is compatible with your battery bank and the
devices you plan to power. You can have 10kW of solar panels in the same system as a 450W inverter or
you could have one 100W panel in the same system as a 7kW inverter. The size of the inverter just limits
the size of the devices that your system can power, which affects how quickly the battery bank is drained.
Inverter size has nothing to do with panel count.
Are these 12V or 24V panels?
Panel voltage varies depending on temperature and brightness and load. The typical operating voltage of
these panels is 18.5V. If the panel was exactly 12V there wouldn’t be a large enough differential between
the panels and the battery for current to flow from the panel to the battery. If you find panels advertised as
“12V” they likely aren’t actually 12V panels. If they were 12V panels you wouldn’t want them for charging
12V batteries because they wouldn’t work. The charge controller changes the output of the panel from the
18.5V to around 13.5V that would be fed onto the battery.
If the charge controller is lowering the voltage, am I losing power?
Power equals voltage multiplied by current (amps). When the charge controller lowers the voltage it in-
creases the current, like a transformer.
My equipment is connected correctly but I’m barely getting any current, why?
Check the voltage of your battery bank. If it is over 13V the charge controller may be reducing the flow to
prevent over charging the battery. This means your system is working perfectly. If the battery voltage is
low, the battery may be damaged. If the problem persists, contact Grape Solar customer support.
GS-100+KIT EXPANDABLE PHOTOVOLTAIC
POWER GENERATION SYSTEM
CONFIGURATION MANUAL Rev. 140303
Valid from March 2014