I've began to notice that after driving for some time without braking at all, my lights dim when I brake.

I've only recently noticed this after moving to the country. Not too many stop signs or lights, so it gave me a chance to notice this.

I've never had any sort of electrical issues (well, save for a fast blinker with no blown bulbs, but that's over now). This has been going on since before the light bulb anyway though.

EDIT: (03/24/2008)

I have done an alternator and battery check and have replaced the Optima battery since it was holding a low charge.

A thread regarding the battery is here: https://honda-tech.com/zerothread?id=2250029

Since replacement of the battery, the alternator has been getting better test results.

03/18 the alternator was tested (before the battery was replaced) and came out to:
Regulator Volts: 14.05
Peak Amps: 55.8
Diode pattern is good.
(Test was done after car had sat for 3-4 or more hours.)

03/21 the alternator was tested again. This is a few days after I replaced the battery with a new one. The results were:
Regulator Volts: 14.14
Peak Amps: 64.9
Diode pattern is good.
(Test was done immediately after a half hour drive.)

The alternator is the stock 75 amp alternator, so that means the alternator went from 74.4% efficiency (55.8 amps) to 86.5% efficiency (64.9 amps) after changing out the crappy battery.

The problem is, my lights have been observed to dim in the same fashion at least once since then. Now, I haven't often been in the position to check if the lights are dimming (work schedule changed). So I don't know if it's doing this or being in the same situation to cause the lights to dim every time.

Does anyone else have any idea why my lights might be dimming? This reminds me of a similar problem I had six years ago with a 1997 EX coupe I had at the time. The lights were dimming occasionally on that car, but Honda wasn't able to replicate the issue (they only had the car during daylight hours).

Neither the old '97 EX or the new '98 EX have shown any other symptoms to an issue (save for the low battery and alternator readings on the current car - both issues which have been resolved).


Modified by NOFX at 9:18 PM 3/24/2008

 

Check your battery connection. Are your + and - terminals tightened. This happened to me when my terminals where loose.

 

Loose connection or alternator going bad.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by ferio252 &raquo;</TD></TR><TR><TD CLASS="quote">Check your battery connection. Are your + and - terminals tightened. This happened to me when my terminals where loose. </TD></TR></TABLE>

same happened to me

 

x2

 

Did an alternator test today.

14.05 Regulator volts.
55.8 Peak amps.
Diode pattern is good.

I tested the battery (Optima Red Top purchased and installed on 02-17-2006). It says it's a good battery, but has a low charge. This is a maintenance free battery and I've never had any issues with it before. So I don't understand why it'd recently begin to lose it's charge.

Since it's a dry cell battery I can't put it on a normal charger. Can someone confirm how to charge it?

If I can't charge it, I'm still within the 36 month free replacement and the seven year warranty.

 

Oh, and I had my boyfriend check the cables the other day (forgot to today and only remembered earlier when I was at work and he was home - so I called and had him check).

He said they were very tight. They wouldn't even move.

I'm thinking I'll clean the terminals in the next couple of days.

I tried to replicate the issue with dimming lights tonight. While driving, I thought I felt a breeze, so I checked my driver's power window. The lights dimmed.

Later on, I tried going on the brakes at different speeds. No reaction from the lights. Even at the end of the road when it'd usually do it.. nothing.

So I don't know.

 

Anyone know why a just over two year old Optima Red Top might have a low charge? No parasitic drain and no previous issues.

I'd rather not turn it in on the warranty trade because though I'd get one of the brand new Optimas there, one of my two managers would end up keeping my current battery since it's still a good battery (just low charge).

Also, could anyone confirm on how to properly charge an Optima battery?

 

Any help with the light dimming is appreciated. I've updated the situation in the first post.

 

are you a guy by any chance?

 

No, NOFX is a woman.

 

check your grounds maybe thats your problem

 

what do you define as dimming?
are we talking almost turning off dimming or dropping a little type of dimming.

The alternator will put out a higher voltage under higher loads, but it will also throttle back the charging when under idle conditions to help the car idle smoothly. Is this what you're seeing?

Can you run a volt meter to the battery terminals while you drive?
Watch the voltage when you are cruising vs at a stop light. It should remain above 12.8, but it may change from ~14.2 to 12.8. With the headlights on, that voltage change is noticeable. Especially if you have the wipers, blower fan and headlights on.

 

At my work we have optimas in all the company vehicles and this is what we were told to do to charge them:

1) Charge the battery at a minimum 100 amps for 15mins(14.5+ volts)
a) Let cool for 15 mins
2) Repeat step one four times-after letting the battery cool for 15 mins after each charge
3) Charge at 2-10 amps(trickle charge) for 24 hours minimum
4) Test the battery


We were told that no matter how much the vehicle is driven the alternator is never enough to keep them charged-apparently they require a minimum 100amp alternator.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by JDM Lyfestyle &raquo;</TD></TR><TR><TD CLASS="quote">We were told that no matter how much the vehicle is driven the alternator is never enough to keep them charged-apparently they require a minimum 100amp alternator.</TD></TR></TABLE>
who told you that? (yellow, blue or red top?)
Maybe if you require a true 100% charge every time. But even an 80% charge is more than enough to start a car and run it for hours even without the alternator.

As far as optimas needing something other than the alternator to charge it...
The redtop is designed to be a direct replacement for stock automotive batteries.
I've have had a redtop for &gt;9 years. I've had zero problems even with the stock 75amp honda alternator. It's never failed to start my car even in -35* chicago weather.
The yellow does work fairly well as an automotive battery, but it doesn't produce as much of a solid base for starting the car, but it will run a large stereo system for hours on end without complaining.
The bluetop is a little different, it may require a little more care but it's also not designed for automotive use at all.

 

It was my boss at work told me,but he never said where he got the info from..he typed it out and taped it on the wall where we keep the battery chargers.
As for which colors it applies to Im not sure,it probably should be different but we have blue tops to start emergency diesel generators and yellow tops in the trucks and charge them just the same.

I agree that 80% is still enough to start a car and run it but i think the reasoning behind them saying that was we are supposted to always have the batteries fully charged,and the fuel tanks full incase something happens.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Relic1 &raquo;</TD></TR><TR><TD CLASS="quote">what do you define as dimming?
are we talking almost turning off dimming or dropping a little type of dimming.

The alternator will put out a higher voltage under higher loads, but it will also throttle back the charging when under idle conditions to help the car idle smoothly. Is this what you're seeing?

Can you run a volt meter to the battery terminals while you drive?
Watch the voltage when you are cruising vs at a stop light. It should remain above 12.8, but it may change from ~14.2 to 12.8. With the headlights on, that voltage change is noticeable. Especially if you have the wipers, blower fan and headlights on.</TD></TR></TABLE>
They don't almost turn off of anything. They noticeably dim. I come around the corner to my turn, don't brake in the smooth corner usually. Then I come to my turn, which has a street light under it. Since I brake before I get to the corner, I can see the lights dim. Once I'm under the street light, I can't tell of course.

So it's a slight dim I suppose... but that's kind of difficult to describe and I doubt either of the cameras I have here could accurately depict the differences in light output.

I don't usually have wipers on unless I need them (rains a lot here, but I prefer not to use them unless necessary). The blower is almost always on. And at night of course the headlights are on, along with the foglights usually.

I'm not in the position right now to run a volt meter to the battery during a drive.

 

If you can't get a meter to the battery, one of the simple ones that plug into the lighter would be better than nothing... there's one that autozone has carried for a while that sits in the same area as the battery terminals. It's a slow response meter and it will be isolated from the actual battery, but it will show you just how much of a dip you're seeing.