LED tail light bulbs? LED replacement for BA15S R5W bulbs
 

For the last few months I've been testing many different LED tail light and indicator bulbs which would be direct plug and play replacements for our standard halogen tail light and indicator bulbs without the need for resistors. I'm finally getting close to sourcing the full set, however I'm struggling to find suitable LED replacements for the R5W BA15S bulbs.

My findings are pretty much 90% of LED tail light bulbs are 21w replacements. The tail lights on our cars are 5w so are dimmer than the brake lights (as they are on all cars). I ordered some which were mean't to be 5w LEDs but tested them today and clearly aren't 5w as they're also the same brightness as the tail lights.

So just wanted to ask, has anyone on here ever successfully sourced any LED replacements for the tail light bulbs which aren't too bright?

Thanks
Rick

They are out there Rick, I fitted the full set over 5 years ago now, sorry I cant be any help as to where to get them from though.

Are your tail light LEDs roughly the same brightness as what the halogens were? All the ones I've tested so far have matched the brightness of the brake lights, so all have been 21w equivalents even when advertised as being 5w.

Definitely dimmer than the brake lights Rick

Isn't a 5W conventional filament bulb approx. = 0.8-1W LED

I have fitted 10w bulbs(notled) in my face lift MGZT and wifes rover216(1999) and previous Rover 100 and daughters Rover25 because T thought 5w abit dull, Ive never had any problems in the car or with other drivers. Tail lights or obligatory lights I talking of. Chris.S.

Something like that. The light output (per watt) of an LED is typically five to eight times that of a filament bulb. The traditional way of specifying vehicle bulbs by wattage is not directly applicable to LEDs. Fitting arbitrarily selected LEDs might break the regulations, but I guess we all have more important things to worry about nowadays.


TC

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I love these questions when is a 5 watt bulb a 5 watt bulb?
The motor industry, sorry that is unfair the governments ministry of Transport, are still living in the 1920s. The output of light from a bulb should be measured in candela, lux, or any other kind of true measurement. The wattage that we use for bulbs in cars and many household bulbs is the power consumption of a tungsten filament incandescent bulb. The bigger the filament the more power or watts it consumes also the more light it produces. The colour of the light ie: yellow blue pure white is dictated by the temperature the filament burns at and the gas the filament is enveloped in.
Equatorial daylight has a temperature of 5800 Kelvin.
The rear bulbs fitted to our cars are tungsten filament bulbs with a temperature around 3200 Kelvin. Lux I would need to measure.
I now know why nobody has tackled bulbs light output.

Tungsten bulbs are the standard by which wattage is judged

A fluorescent tube has about three times the light output of tungsten bulb for wattage power consumption, and depending on the powder and gas makeup inside the tube can be at a temperature between 2800 & 6000 Kelvin

By putting halogen gas in a bulb you will get around 18% more light at around 2000 Kelvin hotter so whiter than an ordinary bulb

Discharge lighting would be the next step up a ballast strikes an arc between two electrodes which is then maintained. The colour of the light is affected by the gas in the bulb. Sodium will give you street light yellow, Mercury Vapour gives you a blue light. Depending on construction they can give you anywhere from two to three and a half the amount of lux developed by a tungsten bulb. When fitted to cars they are usually called xenon headlights.
Once the arc is struck they consume much less power for the same or more light and in cars are around 6200 Kelvin.

Then we come on to the wonderful world of Light emitting Diodes.
They have come on leaps and bounds in the past 10 years. They will progress further in the next decade.
You get between 5 and 7 times the amount of light per watt consumed by that of a tungsten bulb. So a 0.73watt LED bulb will give you the same amount of light output as a 5 watt tail light bulb.
LEDs can also give a temperature range of 2000 to 8000 Kelvin

A car headlight can not exceed 55 watts dipped and 60 watts on main beam. There is no restriction on the temperature of the light or the Lux or candela the bulb puts out.

Now you know why you are blind when a modern LED light car comes at you the bulb may only consume 20 watts of power but can be putting out 3 times as much light at a much higher temperature than your 55 watt halogen bulbed car.

Some day the light output of a bulb will be measured in the proper way but how do we educate ourselves to understand what the numbers all mean.

Did you know that many of the LED bulbs sold today are computer printed.

I wish I had never started this post. But it is all good information.

Alan

One point to mention, there are strict rules regarding light colour temperature at the front especially. Granted, those rules are generally printed in terms of 'not blue's etc, but colour temperature is mentioned in the legislations (if I recall, mot centres here in ni, prior to their shutdown in January, were supposed to be getting equipped with colour temperature readers)

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All really good data, thanks.
Whilst the front bumper was off I've just replaced my W5W front sidelights with 14 LED array units. Best I could find were described as 'white' with some note to the effect this was not 'blue white' so they should be somewhere on the 3800-4800K scale. Just switched them on once to make sure the polarity was correct and not tried them at night yet but first impression is - much much brighter than the filament bulbs they replaced (as you'd expect) and the colour pretty well matches the OEM xenons (it's difficult for the human eye to compare accurately) so they'll do me, now let's see how long they last!