Why Do You Need a Current Regulator
With LED Light Bulbs?



Copyright © 2005-2009 Bebi Electronics, Ltd.




A ‘regular’ light bulb is controlled by voltage.  If you connect a 120 volt ‘regular’ light bulb to 240 volts, it blows up.  LED’s are different.  If the current is too high, it blows up (fails open).

Many other ultrabright white LED products, such as those produced for the automotive market use a simple and cheap ballast resistor for current control.  This is fine for automotive and products that rely on wall power (constant voltage), but it is not good enough for battery storage systems.

Please note that we did not disassemble this light. After it fell apart in Marine use, a cruiser passing thru Savusavu (and a new customer for life), gave it to us to use as an example to others.


A ballast resistor that will protect an LED at 16 volts will produce (roughly) 40% less light at 11 volts.  A ballast resistor chosen for a rated light output at 11 volts will have a very short life.  It for this reason that LED’s made for the automotive market aren’t good enough for off-grid power systems.

A step up from the cheap dropping resistors shown on this page is what is called a 'charge pump' regulator. This device is made by the squillions for the LED flashlight market and is usually ok for 12 volt systems. It does have a small efficiency advantage over our linear regulator at the higher charge voltage seen by the batteries (on the order of 0.010 amps), but we don't think the advantage to the consumer is great enough to give up our secondary business goals (providing employment to a disadvantaged community).

Click to Enlarge
Another disaster waiting to happen. The photo at the right shows you the 23 ohm resistor. At 12.75 volts, the light will run at 41 milliamp/LED, double the rated maximum current per LED. If the light was left on during an equalization charge, it would draw 58 mA/LED, or almost three times the rated maximum. Instead of more than 100,000 hours, this light will be lucky if it made it 1000 hours without exhibiting signs of failures!


Unfortunately, a charge pump regulator doesn't do so well on a 24 volt system. The fly in the ointment is that these regulators are made for a MAXIMUM of 30 vdc, which is under the maximum that your system can see during an equalization charge. 'Oh well', sez you, 'I'll just turn the light off while I'm charging'. Prudent electronics design practice calls for a 100% safety margin in a critical circuit (our products meet this requirement). Just how critical do you think your running lights are in a crowded waterway?

I couldn't let this one go. A post-mortem showed that this unit, which was marketed by an otherwise reputable major retailer (and, ironically enough, is also owned by a prince of a guy, who's a real sailor to boot) is in reality an automotive tail-light bulb! Even though the package claims a draw of 0.06 amps, the reality of the values of the resistors shown for you to look at indicates a minimum draw of 0.109 amps at 12.75 volts. Depending on how the unit is wired, it could actually be as high as 0.250! Even if is wired correctly (no directions given or included), the draw through the LED strings is .085 amps.  
  This means that each of the two main LED series strings could be running as high as 0.1275 amps at 12.75 volts, or 638% ABOVE THE MAXIMUM ALLOWABLE DRIVE CURRENT OF THE LED!!. And can you imagine actually having a light on while running your engine: 0.144 amps at 14.4, 720% OVER MAX! It is our opinion that reliability is paramount in a boat. I'm not aware that the USCG or ABYC (look at the enlarged piccie) has any specific recommendations for cabin lights, but if they did, I think they need to be reconsidered! What do YOU think?


The last basic type of current regulator is what is called a PWM (pulse width modulation) regulator. This is the most efficient type of regulator, but it does (currently) suffer from a cost an order of magnitude above that of our regulator and if improperly implemented, will cause interference ('hash') on your VHF and HF ('SSB') radio. If you'd like some further reading about these types of problems which can occur, you might want to follow this thread on the SSCA Discussion Board.



Besides being truly waterproof, Bebi Lighting Products are designed and manufactured from the bottom up to work in a harsh, off-grid power environment.  We use a linear current regulator, which provides adequate light while protecting the LED’s. Our Malosi ® series of lights actually incorporate two regulators to provide an addition margin of safety whilst operating a vessel at night.

In addition to our current regulator, we 100% test and sort our incoming LED's.  Not only should this prevent a bad LED from the manufacturer from entering our product, but it also yields another two benefits:  First, there is a large difference from the manufacturers in the LED properties (Forward Voltage Drop), which effects emitted color and intensity of the LEDs.  Our matching method ensures that the lights are pleasing to the eye.  Second, it prevents any one LED in a series string from pulling more current than the others.  Since failure of the LED's are based on the amount of current drawn, this further prevents the possibility of a single LED to exceed it's rated current.

Knowing that a warrantee is worthless 1000 miles from shore, we also perform a 100% burn-in on all of our products for a minimum of 6 hours. You might think of our products as 'just another light bulb', but we think of them as being an important aid to navigation and lavish as much care and testing on them as you dream a radar or a GPS receives!

Between the inate protection of our current regulator, our exclusive resin blend, our exhaustive testing and the nature of LED’s, we are comfortable extending a limited lifetime warrantee for our products.