Battery Systems

 When choosing a solar battery system, you can consider things like your daily power load, the efficiency of the panels, and the minimum warranted power. It's also recommended to check the PV USA test conditions (PTC) rating and the suitability of the installation location. 

 There are four main types of battery technologies that pair with residential solar systems:

• Lead acid batteries.
• Lithium ion batteries.
• Nickel based batteries.
• Flow batteries.

 When choosing a solar battery, you can consider things like: 

• Battery capacity: Battery capacity is measured in kilowatt hours (kWh) and indicates the amount of energy you can store.
• Cycle life
• Voltage
• Monitoring
• Inverter compatibility
• Safety

  Energy usage is measured in kilowatt hours (kWh). For example, if a home uses 1,000 watts for eight hours per day, then the energy usage is 8 kWh per day. 

Add the wattage of all the appliances you will be using and estimate the hours they will run per day. Don't cheat yourself and be realistic when calculating loads.

 Battery Bank Sizing for an Off-Grid System

1. Battery bank size (kWh) = Daily energy use (kWh) x Number of days of autonomy / (1 – SOC)
2. Battery bank size = 1.9 x 3 / (1 – 0.5) = 11.4 kWh. ...
3. Amp-hours = 1000 x Energy storage (kWh) / Battery Voltage (Volt)
4. Amp-hours = 1000 x 11.4 / 48 = 237.5Ah at 48 Volt.