Fog Lights and Battery/Alternator Longevity

[OriginHacker21]

Originally Posted By: satinsilver
How much was it to replace the cracked fog light? I have a cracked fog light on my 05 Toyota Matrix(driver's side). Don't want to spend a small fortune trying to fix it.


I paid about $80 + $10 shipping for the fog light OEM. I wanted to go OEM cuz my car is brand new. Dealer wanted $150 for the light and $150+ for labor (said 2+ hours) and quoted me around $400. Took me 3 mins to do it myself after watching a youtube video.

http://www.hondapartsunlimited.com/oem-p...r/33901-tr0-a51

 

[JHZR2]

Originally Posted By: OriginHacker21
Originally Posted By: JHZR2
You just look oh so cool running fog lamps at all times!!

I did a calculation a while back regarding the long term costs of running lights.

See here:

http://www.bobistheoilguy.com/forums/ubbthreads.php?ubb=showflat&Number=3065795


Actually I stopped using my fog lights right after starting this thread thanks to your advice. Serious - stopped using them. I only recently had to deal with replacing one because my front left fog light shattered (not sure how) - and I had to replace it.

So haven't used my fog lights for a long time - other than to test the leveling of the new fog light I just installed yesterday.

I appreciate the time you took to respond with all that info. Was really awesome

Actually, I'm completely confused. I'm a passenger on a long drive and was posting in another thread - or so I thought.

Thought I was cross referencing my post into another, different thread.

Too many miles on the road apparently...

Cheers!

 

[OriginHacker21]

Originally Posted By: JHZR2


Actually, I'm completely confused. I'm a passenger on a long drive and was posting in another thread - or so I thought.

Thought I was cross referencing my post into another, different thread.

Too many miles on the road apparently...

Cheers!


All good! Hope you have/had a great trip.

 

[Clevy]

Originally Posted By: JHZR2
Originally Posted By: 1999nick
I have a rather low opinion of anyone deliberately using their fog lights when there is no fog.


Me too.

But let's do the math... what is a foglight bulb, like 55W for an H1 I guess? So burning two of them is about 110V... 110W/14V=~8A.

So on a 120A alternator, youre using around 7.5% of its capacity.

Lets assume you drive 120000 miles with them on over the lifetime, at an average of 40MPH. That's 3000hours of foglights burning.

3000hr*110W=330000Wh or 330kWh. A gallon of gas is about 33kWh, but an ICE is only around 25% efficient, and an alternator is maybe 75% efficient. So, to get 330kWh you need to figure it out:

1 gallon of gas is 33kWh thermal, which is 33kWht*0.25kWhb/kwht*0.75kwhe/kwhb=6.18kWh electric /gal

So to make 330kWh, youll need to burn 53 gallons of gas.

So at $3.50/gal, burning your foglights will cost you $187 plus bulbs.

Higher loading on the alternator will shorten its life, but how much is dependent upon rating and how much else you put on it.

Burning foglights and headlights (assume 220W and the battery voltage, as opposed to alternator voltage is 12.6 of less) takes around 20A.

Reserve capacity is hpow many minutes a battery will discharge at 25A. A group 51 battery will have an RC of abour 65 minutes, so at 20A vs 25, it will be more like 70 minutes.

So youll deplete around 1.25% SOC each time you do this. Personally, I wouldnt unless you drive very far compared to the number of times you do this. 60 seconds will more than deplete a surface charge, and then your battery will sulfate, getting worse since the next load it sees is the starter. If you had a group 49 or an H9 battery, it might not be a hige deal, but no way Id do it on a wimpy honda electrical system/small battery.


Wow. Talk about detailed. Thanks
Enlightening.