Synchronised bulb failure

[MarkyG82]

Had both dipped beam (h7) bulbs go a matter of seconds apart this afternoon. Could have blown at the same time it just took a few seconds for the first message to complete it's warning?

Anyway. What could have caused them to fail at the same time? They have only been in since October so quite disappointed in the life (osram night breaker). I hit a big pothole the other day which was big enough to dislodge bb8 from his holder in the dash. Maybe related?

 

Any tips on how to avoid early failure?

[cheezemonkhai]

The plus 50% bulbs have finer wire for the extra brightness, so fail sooner.

 

bumps plus the fact they have shorter life probably combined.

 

Look at the +30% and the plus 20% long life. A good plus 30 is as good as an average to weak plus 50 but usually last a lot longer.

Edited 19 January, 2020 by cheezemonkhai

[aki78]

The same thing happened to me in the past. A massive pothole and both high intensity bulbs failed at the same time.

[MarkyG82]

Thanks @cheezemonkhai. Replaced with halfrauds +50 which are noticeable dimmer so we'll see how they last. £16 a pop so more spendy than the £21 for a pair of osram on Amazon. May get another pair from Amazon and put the Halfords ones in the box for spares.

 

@aki78 I have hit some pot holes this week that were hidden by puddles. Annoying thing is I drove to my dad's Friday night with the lights working fine then the next day they fail. Maybe they cooled down and the tension pulled then apart.

[cheezemonkhai]

Not sure if they’re still as good, but last time I had halogens and did high annual mileages I used osram silverstar bulbs.

 

The shock from the pothole then the cooling was probably enough to push a bulb a good way through it’s life beyond it’s limits.

 

Next time you change a bulb after a good few hours of use take a look at the filament and you’ll see the degradation of the wire.

 

Also compare the plus 50 filament at new and a long life, standard or plus 30 and you will notice the finer wire.

 

With a fixed 12v, 55w, there are few ways to get that extra light. Burning a finer filament means more light from it, but also less life.

Edited 19 January, 2020 by cheezemonkhai

[MarkyG82]

That's really good info. I did wander how they produced the added light. I think I'll stick with the Halfords ones for now as on the way home last night they weren't the worst.

[cheezemonkhai]

Did you go for their own brand ones or the GE /premium ones?

 

This was years ago, but I found their own brand all weathers were actually very good for fog etc and better than the big brands.

 

On the other hand I vaguely seem to remember their brighter bulbs were not as bright as the brightest but did last quite well.

 

It’s always a balance as you can’t have something for nothing. You may find they in fact last well (or not, only time will tell).

 

Do let us know how they go though, as decent bulbs are worth knowing about.

 

 

[gregoir]

As to why it happened? Factually, good quality control and consistency of manufacture. 🤐

Edited 20 January, 2020 by gregoir