Possible causes

• Poor connection between battery and controller

• The battery voltage is low or the battery is faulty or disconnected

• Faulty controller

Solutions

• Ensure that the battery terminals are properly connected

• Measure the battery voltage – it should be no lower than 11V DC when placed under load.

• Check for corrosive build-up around the battery terminals.  If there is corrosion, replace both the battery and terminals

• Replace the battery

• Ensure that the ‘Mains Present’ icon is solid

• Replace faulty controller