1. The voltage of the solar panel is usually stable from morning to night (when exposed to the sun), basically around 30V, but the output power always changes in the morning, evening, noon and noon. If the quality is good, the solar output can reach 240W at noon.

         2. Your system is a 12V system, but the battery voltage is too high, so it is not suitable for use with 30V/240W solar panels. Generally, the charging voltage is 1.5 times the battery voltage. In other words, for the 12V battery pack, the 18V solar panel is correct.

         3. When charging a 12V battery, the power is actually much less. In the case of an ordinary controller, the charging voltage is equal to 18V. This is about 18 x (240 / 30.2) = 143w solar panels.

         4. If the controller is an MPPT controller, the above problem is not a problem. The MPPT controller has a wider input voltage range. At the same time, it can convert more voltage into current for charging, which also enhances the battery protection capability.