Brake module or battery?

[LeftieBiker]

I never noticed it on the 2011 because I did not monitor the 12V system while driving, but the 2015 and 2019 do run the system at 14V with wipers on (and for a little while after turning them off). I have not noticed the same voltage rise with just HVAC use (which is why I asked for your explanation).

I wrote that it was anecdotal because it was based more on descriptions of use patterns than of measuring system voltage. I'm surprised that specific device activation, rather than a drain of any sort on the 12 volt system, is required to increase charging. I guess I'll never understand Nissan engineering...

[eeeefarm]

Update: I did take the car in to my Nissan dealership this morning, because I had made an appointment, and I was pleasantly surprised that they listened to what I had to say, the mechanic tested the battery....weak but not horrible....and they are going to see if they can order me in an Optima Yellowtop to replace it. They didn't charge me for checking the battery. So I am pleased with the service so far....

[LeftieBiker]

Great! Ask them to fully charge the battery before installing it, as Leafs can sometimes be slow to do that themselves.

[Nubo]

...
You're not going to notice a headlight brightness change with just a volt to 1.5 volts change in battery voltage.
...

Oh, you definitely would, IF the voltage change was reaching the bulbs. Incandescent bulb output is highly voltage dependent.*



Headlights in many vehicles are strangled by resistance from too-thin wiring. I keep meaning to try rewiring the LEAF's high-beams but I hardly ever use them.

*I learned this empirically when I was a kid. My dad had a vehicle with electric windows (fancy at the time), and riding in the back seat I noticed if I activated the motor to "close" the already-closed window, the headlights would dim. If I stretched myself out to operate both windows at the same time, the dimming was quite noticeable. For months my dad thought the car's electrical system was on the fritz as I made the lights dim and brighten randomly. I finally had to confess as he was getting ready to take it in for repair

[lorenfb]

...
You're not going to notice a headlight brightness change with just a volt to 1.5 volts change in battery voltage.
...

Oh, you definitely would, IF the voltage change was reaching the bulbs. Incandescent bulb output is highly voltage dependent.*



Headlights in many vehicles are strangled by resistance from too-thin wiring. I keep meaning to try rewiring the LEAF's high-beams but I hardly ever use them.

*I learned this empirically when I was a kid. My dad had a vehicle with electric windows (fancy at the time), and riding in the back seat I noticed if I activated the motor to "close" the already-closed window, the headlights would dim. If I stretched myself out to operate both windows at the same time, the dimming was quite noticeable. For months my dad thought the car's electrical system was on the fritz as I made the lights dim and brighten randomly. I finally had to confess as he was getting ready to take it in for repair

Yes, there's an obvious change of lumens (dl) per voltage change (dv), but at what dl/dv can the eye detect/perceive a change
and at what level of ambient light. A perfect example is Lefti's testing of a Leaf's battery voltage change with the wipers on
by monitoring the headlight brightness change, i.e. he saw no detectable brightness change and assumed that the voltage
didn't change. So given the number of tests for battery voltage change with the wipers on, it's now a known fact that the
battery charging voltage changes with the wipers being on. Conclusion; The eyes make a poor detector for a small dl/dv.

[Nubo]

Yes, there's an obvious change of lumens (dl) per voltage change (dv), but at what dl/dv can the eye detect/perceive a change
and at what level of ambient light. A perfect example is Lefti's testing of a Leaf's battery voltage change with the wipers on
by monitoring the headlight brightness change, i.e. he saw no detectable brightness change and assumed that the voltage
didn't change. So given the number of tests for battery voltage change with the wipers on, it's now a known fact that the
battery charging voltage changes with the wipers being on. Conclusion; The eyes make a poor detector for a small dl/dv.

My point was the power to the lamps may be resistance-limited by marginal wiring, in which case a 1.5V change at the battery may not translate to a proportional change at the lamp under load. Had the lamp indeed seen such an increase in voltage, the output should be up by 50%, and the color temperature would change as well. I wouldn't conclude this is imperceptible without confirming the actual voltage levels applied to the bulb.

[lorenfb]

Yes, there's an obvious change of lumens (dl) per voltage change (dv), but at what dl/dv can the eye detect/perceive a change
and at what level of ambient light. A perfect example is Lefti's testing of a Leaf's battery voltage change with the wipers on
by monitoring the headlight brightness change, i.e. he saw no detectable brightness change and assumed that the voltage
didn't change. So given the number of tests for battery voltage change with the wipers on, it's now a known fact that the
battery charging voltage changes with the wipers being on. Conclusion; The eyes make a poor detector for a small dl/dv.

My point was the power to the lamps may be resistance-limited by marginal wiring, in which case a 1.5V change at the battery may not translate to a proportional change at the lamp under load. Had the lamp indeed seen such an increase in voltage, the output should be up by 50%, and the color temperature would change as well. I wouldn't conclude this is imperceptible without confirming the actual voltage levels applied to the bulb.

Remember, your graphic is for incandescent bulbs, and not for LEDs which the Leaf uses for low beams. Typically LED headlights
are internally voltage regulated, and as such have a constant brightness with about a +/- 10-15% change in battery voltage.

[cwerdna]

Remember, your graphic is for incandescent bulbs, and not for LEDs which the Leaf uses for low beams. Typically LED headlights
are internally voltage regulated, and as such have a constant brightness with about a +/- 10-15% change in battery voltage.

On the bolded part, not on my '13 SV. '13 to '17 S trims only have halogen headlights. '13 SV and I believe all the way thru '17 SV only had halogens are standard. You had to get the quick charge + LED headlights package in order to get LEDs headlights on that trim.

My former '13 SV w/both packages had LED headlights and CHAdeMO.

[Nubo]

Yes, there's an obvious change of lumens (dl) per voltage change (dv), but at what dl/dv can the eye detect/perceive a change
and at what level of ambient light. A perfect example is Lefti's testing of a Leaf's battery voltage change with the wipers on
by monitoring the headlight brightness change, i.e. he saw no detectable brightness change and assumed that the voltage
didn't change. So given the number of tests for battery voltage change with the wipers on, it's now a known fact that the
battery charging voltage changes with the wipers being on. Conclusion; The eyes make a poor detector for a small dl/dv.

My point was the power to the lamps may be resistance-limited by marginal wiring, in which case a 1.5V change at the battery may not translate to a proportional change at the lamp under load. Had the lamp indeed seen such an increase in voltage, the output should be up by 50%, and the color temperature would change as well. I wouldn't conclude this is imperceptible without confirming the actual voltage levels applied to the bulb.

Remember, your graphic is for incandescent bulbs, and not for LEDs which the Leaf uses for low beams. Typically LED headlights
are internally voltage regulated, and as such have a constant brightness with about a +/- 10-15% change in battery voltage.

Agreed; LED are a different animal. I was referring to Leftie's high-beam test.

I was very happy when LED lighting sufficient for bicycle lights came along. Prior to that I'd been using severely over-volted halogen bulbs which died young and then for a while a remarkable 10W arc lamp which was amazing but didn't want to spark in cold weather. Being able to throw 200+ lumens for 90 minutes with a single rechargeable AA battery is like a miracle.

[LeftieBiker]

The only downside to the LED revolution is the market being flooded with crappy blue Chinese LEDs.