Topic: LED light burnout?

[SamP]

So I updated all gauge lights and taillight to LED, and added two small LED white lights under the tail to give me proper lighting on the plate.
Turned the bike on and off a bunch of times to test something else and it wasn't until after several of my LEDs stopped cutting on that I became aware of a flicker that was happening when the ignition was turned on - voltage surge.
Is there a separate voltage regulator I need to install, or are these smaller LEDs just too delicate for these old electrics? Just switch back to incandescent for all dials and gauges? Is my tail light at risk of dying the same death? 1977 cb550k if it makes any difference.
Thanks.

[russouno]

If you are wiring up the LEDs directly to the power (12v) they are not going to last very long.  5v max on LEDs.  You may have something else setup with resistors, but from what it sounds like, they are directly wired up to 12v?

[SamP]

If you are wiring up the LEDs directly to the power (12v) they are not going to last very long.  5v max on LEDs.  You may have something else setup with resistors, but from what it sounds like, they are directly wired up to 12v?

They are directly plugged into where the incandescent bulbs would be for idiot lights, gauge plates, and taillight. This goes through all the wiring and fuses that it's supposed to, and therefore shouldn't be 12 volts, just the voltage necessary to light a(n incandescent) bulb. Thing is, when I turn the ignition on or off, there's a flicker of excess power which is damaging and burning out the lights. I read somewhere that LEDs are subject to damage from voltage fluctuations, and that's exactly what happens when the ignition is turned on or off, so I figure I'm burning them out.
If I need a resistor installed somewhere, I'd appreciate guidance in purchasing that as well as where to install it.

Sent from my LG-H811 using Tapatalk

[Bodi]

Give us the part number for the LEDs you used, then we can tell what's happening. Some replacement LEDs have resistors built in the socket to connect to automotive 12VDC and some don't.
There's no voltage "surge" above battery voltage when a bike's key goes on - maybe a bit of a spike when it goes off as the coils discharge.
Overcurrent LEDs can flash bright and then dim down. That's not good.

LEDs are not at all like normal bulbs (except for turning electricity into light). They work on current - amps - not voltage. All LEDs will need either a series resistor if connected to a voltage source, or run off a current source. Some novelty LED devices omit the resistor with tiny button cells... OK for toys but don't try it with something you expect to last a while.
Each LED will have a specified forward voltage drop and operating current. To find the resistor needed you just use good old Ohm's Law:
R= (Vsupply-Vforward)/I
Example... for a 40mA (0.040A) LED with 3V forward drop on 14V bike power
R= (14-3)/0.04 = 275 Ohm

To keep brightness constant while supply voltage changes, current source drivers are readily available and super easy to make yourself with cheap and common voltage regulator chips.

[SamP]

I'm using 11 of these - https://www.superbrightleds.com/moreinfo/ba9s-ba7s/ba9s-led-bulb-1-led-ba9s-retrofit-car/958/2359/ - 4 in the gauges, 2 over the plate, and 1 each for oil, neutral, hi beam, and left and right turn signal. I wired the two over the plate up with the gauge lights, so they're always on (tried to with the tail light but I couldn't get it to work that way).
For the tail/brake light, I've got one of these - https://www.superbrightleds.com/moreinfo/tail-brake-turn/1157-led-bulb-dual-function-1-high-power-led-bay15d-retrofit-car/808/#/attributes/13 - installed.
Actual turn signals are incandescent, though I do have a flasher relay designed for LEDs or incandescents. Headlight is stock, but currently uninstalled. Upgrading to 35/35 H4 shortly.
Thanks for your help and patience. I've tried understanding watts vs volts vs amps vs ohms. I have yet to wrap my head around it, so please forgive me if I refer to the wrong thing in my replies (maybe I'll try some more youtube videos later...)

[gtmdriver]

You need to use automotive specific LEDs.

Even LEDs rated at 12v can fail once the alternator starts charging at up to 14.4v

[SamP]

Really? I've been following this forum for a while and seen these bulbs listed on other members' LED conversions. Unless they didn't follow up with their issues, I never heard anything said to the contrary when these resources were linked.

I'm not saying you're wrong, I just would have thought that this would have come up more often in the forum, given that superbrightLEDs has been listed as a resource before. Seems like a big oversight (and thus one I am likely to make ).

[CB650CPastor]

You need to use automotive specific LEDs.

Even LEDs rated at 12v can fail once the alternator starts charging at up to 14.4v

The bulbs he referenced say they work in a 9 to 15 volt range.

[Chachi]

I use bulbs from there with no real issues, but I assume they just source them from where ever so maybe you have a bad batch? I use a different BA9S for my cluster lights with LED color matching the lens color. I think the one you sent is just white. Also, I think they do have some brighter 1157 dual filament bulbs for tail light applications that the one you linked as well.

>>I wired the two over the plate up with the gauge lights, so they're always on (tried to with the tail light but I couldn't get it to work that way).

Try taking the extra lic plate lights out of the equation and/or tail light bulb and if it still occurs. Rule out each set of lights. It's probably something other than just the bulbs.

[flybox1]

I have been using these for 3 years without issue.  They are not the COB type LED as you were having issues with.
I dont know if this is what is causing the issue.  Its the only difference I can see....

https://www.superbrightleds.com/moreinfo/ba9s-ba7s/ba9s-led-bulb-1-led-ba9s-retrofit-car/3/

[rotortiller]

SamP,

Those instrument LED bulbs worked fine on my CB750. Been using them for 2 years now. The resistor is build in to handle 12 volt systems of bikes and cars. That's how they make their rating on the box. My regulator tops out at 14 volts and a bit. Maybe you got a bad batch of bulbs because a non running bike is 12 volts?

rt

[SamP]

Sounds like I may have gotten a bad batch if everyone else has had these without an issue. I'll be contacting them about replacements or refund. Currently only one of my 6 whites is working. Colored LEDs are fine, but we'll see if a replacement batch doesn't cure the issue.
Thanks for all the responses.