Bianca

The LED lamps most suitable for Marine have a electronic 10-30V constant-current circuit built in. These lamps allow a lamp to give exactly the same light output at say 10V as they would if the voltage was 30V. An interesting read is at http://boatlamps.co.uk/contents/en-uk/d72.html

I'm not sure what you mean by a voltage regulator, do you mean a suppressor designed for spikes or a seporate electronic circuit to regulate voltage to 12v the latter being much more expensive? I ask this because some so called voltage regulators turn out to be simple varistors designed to break down above 12v and protect a device from short duration voltage spikes, generated by fridge thermostats etc.

Be careful buying cheap LED bulbs as they are often controlled by inbuilt resistors and 12v bulbs can seriously overheat at 15v which a typical equalising charging voltage for properly cycled deep discharge batteries. Try http://www.boatlamps.co.uk they sell a vast range of 10-30v constant-current LED products.