Will intermittent voltage as high as 18-volts harm a 12-volt LED Strip?

Will intermittent voltage as high as 18 volts harm a 12-volt LED? I am thinking of using them on my boat whose charging system voltage can vary this high.

As our LED products are designed at the circuit level with a specific voltage in mind, we do not recommend utilizing a higher voltage power supply with a 12V LED strip light product. 

​Generally speaking, connections that could lead to over-voltage can permanently damage the LED strip lights and void the product warranty. We do apologize for any impact this might have on your installation planning.