Taking a baseline on New Headlight bulb

paulsiu

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Sep 8, 2019
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All bulb's output drop as they age, whether they are Halogen, HID, or LED. I often replace bulb when they burn out, but that seemed a bit dangerous. What if the other bulb burn out shortly afterwards before I can replace the burnt out bulb? In addition, the bulb may get too dim and I don't notice because it's gradual.

How about taking a baseline. Could we do something like this:
1. Park car at a measure distance from the garage door.
2. Use a cell phone with meter software to take a reading at the brightest spot.
3. Repeat monthly and chart the output until the bulb burns out.

The reading on the phone may not be accurate, but we are trying to get a relative reading. I could use this to find out how dim the bulb gets until it burns out. We could then chart out when to replace it if for example the output drops by 20% or so.

By the way, when a manufacturer claim they have an output or 1500 Lumen, do they actually measure this?

Paul
 

alpg88

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a bulb has a rated lifespan, lets say 2000 hours, now how many hours do you drive a day? lets say 5. that is 400 days, so just replace your bulbs every year. and never worry about dimming, or burning out.
in my personal experiences, none of my brand new cars that i lease for 3 years needed any bulbs replaced, neither tail lights nor headlights,
 

Lynx_Arc

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I've never had both headlight bulbs on any car go out within the time it takes to track down a replacement bulb for one headlight going out. The problem with determining how long they last can be hard as most people don't drive a lot at night so bulbs can last for 10 years or more and replacing a bulb every year would be a waste of money if it is going to last another 5 years easily (or more). I've had my truck for 13 years and I'm not sure when the bulbs were replaced before that and not had a headlamp bulb go out (normally) I did damage a headlight and had to replace it and the bulb but the other headlight bulb is still going strong. If you are truly worried about having dual bulb failures just buy spare bulbs and keep them in the vehicle ready to change if needed.
 
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delaware74b

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I usually do a group replacement at each end of my vehicles as a bulb fails. IE, a front parking lamp burns out then I replace all bulbs on the front end. I have had vehicles where it's a major undertaking to replace a single bulb (01 Chrysler 300M front end requires removal of front bumper cover for headlights and turn signals). I have gone from that extreme to tool-free front bulb replacement on two different models ('04 Explorer and '04 Ranger).
 

Lynx_Arc

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I can see replacing bulbs that are difficult to get to in an area I have one that blinks out for awhile in my dash and comes back on the next time I drive my truck that if I had to replace it I would have to tear out the dash and would replace every bulb in site there. Bulbs that are easy to get to I don't worry about and headlamp bulbs are easy I had to replace a taillight bulb and a front turn signal bulb and it wasn't hard at all just took time not to strip threads on plastic parts.
 

Alaric Darconville

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What if the other bulb burn out shortly afterwards before I can replace the burnt out bulb?
What happened to your spare?

How about taking a baseline. Could we do something like this:
1. Park car at a measure distance from the garage door.
2. Use a cell phone with meter software to take a reading at the brightest spot.
Not nearly accurate enough.

We could then chart out when to replace it if for example the output drops by 20% or so.
Lumen maintenance of halogen bulbs is typically 90% at B50 (average lifespan), 80% is really low indeed, and the filament will have so many chunks missing and so much dendritic growth, beam focus will be ruined. Bulbs in that state would be dangerous.
The "Plus" bulbs (+80, +100 and the like) don't last long enough to lose much performance.

By the way, when a manufacturer claim they have an output or 1500 Lumen, do they actually measure this?
With an integrating sphere.
 

Alaric Darconville

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It just occurred to me one could put an hour meter on their headlamp circuit to track how long the bulbs have been lit. Then one could get a semi-accurate indication of when to change them.

Heck, luxury cars with HIDs (LOL, remember those?) could have had something like that for a 'maintenance' light (like the oil change reminder) so people could take their car to the dealer to pay too much for their arc-discharge capsules to be changed.
 
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