Headlamp Power Draw

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SageBrush

Well-known member
Joined
Mar 6, 2011
Messages
7,959
Location
NM
I own a 2013 LEAF model 'S' with tech package. I'm hoping someone will know how much power my headlights draw in normal and high beam.

My intent is to do some testing of my 12v battery with the lights as a load; initially to see the voltage drop, and then to monitor the change in voltage over an hour of draw.
 
'13S doesn't have an LED headlight option, unless someone retrofitted them. My halogen Lo/Hi beams are 45w and 65w, to get amperage divide watts by voltage, eg. 45w/13v=~3.5a times 2 for both headlights.
I believe the SV had the option? for LED headlights which were standard on the '13SL.
 
My LEAF does have the DCFC port and rear view camera. Were LED lamps part of the package ? I presume I should be able to tell by just looking at the bulbs in the lamps.

@jjef. thanks. I just googled H13 lamps and found an entry for type 9008 that was spec'd at 55 watt low beam and 65 watt high beam.I'll go with 90 Wh on low beams for the one hour test
 
Sorry about the goof on the LED high beams. I actually didn't know that they weren't part of the S Charge Package in 2013. Does any year S offer them?
 
The LEAF outsmarted me ... for now.
The lamps turn off after less than minute.

Is there a way to keep a 12V load on the LEAF and not energize the DC-DC converter ?
Perhaps the Ig-On state ?

About the bulbs: If I peer into the lamp I can a see a small round bulb on the top that I'm pretty sure is a filament bulb, but the main bulb is hidden behind a blue cowl. If access is easy, I'll pull the large bulb to have a look.

For anyone interested in my battery evaluation games:
All battery readings are from a battery tester doodad I have connected to the battery all the time. I read the voltage and "SoC" from a bluetooth connected app that also logs voltage readings every couple of minutes.
I charged the battery to 'full' on 12/30 -- 12.6 volts
The next day the car was driven ~ 45 minutes
Two days later the battery is at 12.2 volts
-- a 90 watt load (~ 8 A)(low beams) dropped the battery to 11.7 volts
-- fiddling with the headlights for under 5 minutes dropped the estimated SoC by 10%
--- So from a short test the battery capacity is ~ 8*5/6 = 7 Ah. Out of perhaps 35 - 40 Ah when new
 
SageBrush said:
The LEAF outsmarted me ... for now.
The lamps turn off after less than minute.

Is there a way to keep a 12V load on the LEAF and not energize the DC-DC converter ?
Perhaps the Ig-On state ?

About the bulbs: If I peer into the lamp I can a see a small round bulb on the top that I'm pretty sure is a filament bulb, but the main bulb is hidden behind a blue cowl. If access is easy, I'll pull the large bulb to have a look.
I believe if you have the headlights OFF when you turn the car OFF, if you turn them back on with the car OFF they will stay on indefinitely.....Also I believe if they turn off in your first scenario if you turn the switch OFF then back ON, I believe they will stay ON. Not positive but I know at least one of my cars act like that :)
Leftie, I'm not all that familiar with newer Leafs but at least on the older S models, LED headlights weren't an option, no matter what package you got. It's possible the latest Gen 2 Leafs all get LEDs, I just don't know.
 
jjeff said:
SageBrush said:
The LEAF outsmarted me ... for now.
The lamps turn off after less than minute.

Is there a way to keep a 12V load on the LEAF and not energize the DC-DC converter ?
Perhaps the Ig-On state ?

About the bulbs: If I peer into the lamp I can a see a small round bulb on the top that I'm pretty sure is a filament bulb, but the main bulb is hidden behind a blue cowl. If access is easy, I'll pull the large bulb to have a look.
I believe if you have the headlights OFF when you turn the car OFF, if you turn them back on with the car OFF they will stay on indefinitely.....Also I believe if they turn off in your first scenario if you turn the switch OFF then back ON, I believe they will stay ON. Not positive but I know at least one of my cars act like that :)
You've motivated me to fiddle around ;)
So far, I know that in my car if the lights are turned off by the car and then I turn the knob to off and then on again, the lights only stay on for a short time. I'll try you other suggested variations. Thanks !
 
SageBrush said:
--- So from a short test the battery capacity is ~ 8*5/6 = 7 Ah. Out of perhaps 35 - 40 Ah when new

Keep in mind the "standard" AH measurement is sustained load at the 20-Hour rate, so it's a very gentle discharge. E.g., a 40AH battery should sustain a 2A load for 20 hours. The same battery will not sustain an 8A discharge for 5 hours.

https://en.wikipedia.org/wiki/Peukert%27s_law
 
Nubo said:
SageBrush said:
--- So from a short test the battery capacity is ~ 8*5/6 = 7 Ah. Out of perhaps 35 - 40 Ah when new

Keep in mind the "standard" AH measurement is sustained load at the 20-Hour rate, so it's a very gentle discharge. E.g., a 40AH battery should sustain a 2A load for 20 hours. The same battery will not sustain an 8A discharge for 5 hours.

https://en.wikipedia.org/wiki/Peukert%27s_law
Yep

Google found a generic table that says that 51R PbA batteries have 80 minutes of reserve capacity. That test is at 25 A, so 33 Ahr + Peukert
 
I am fairly sure the Leaf will turn its lights off after a short period of time no matter what you do (unless you turn them off/on again after they time out). I know that 2011 had LED low beam with halogen high beam and 2015 SL was the same. They also have a small halogen bulb in each headlight for parking lights (which I replaced with LED bulbs shortly after purchase). My 2019 has LED for both low beam and high beam and LED for park lights. I know that halogen low beams became standard on lower trim models beginning in 2013.

If you want to put a continuous load on the battery to test it, just get a halogen headlight bulb and connect it directly to the battery. If you buy the same bulb as your car uses, you can keep it for a spare.
 
GerryAZ said:
If you want to put a continuous load on the battery to test it, just get a halogen headlight bulb and connect it directly to the battery. If you buy the same bulb as your car uses, you can keep it for a spare.
I had the same idea, but I was unsure how to make solid connections. Advice ?
 
SageBrush said:
GerryAZ said:
If you want to put a continuous load on the battery to test it, just get a halogen headlight bulb and connect it directly to the battery. If you buy the same bulb as your car uses, you can keep it for a spare.
I had the same idea, but I was unsure how to make solid connections. Advice ?

Buy a headlight connector with pigtails (available at auto parts store), attach alligator clips to the ends of the wires, and clip to the battery. You could also use spade terminal connectors on the ends of the wires and push them on to the terminals of the bulb.
 
GerryAZ said:
You could also use spade terminal connectors on the ends of the wires and push them on to the terminals of the bulb.
Thanks, I think I've found an H13 bulb socket with 3 wires for about $7 on Amazon

Sound about right ?
 
SageBrush said:
For anyone interested in my battery evaluation games:
All battery readings are from a battery tester doodad I have connected to the battery all the time. I read the voltage and "SoC" from a bluetooth connected app that also logs voltage readings every couple of minutes.
I charged the battery to 'full' on 12/30 -- 12.6 volts
The next day the car was driven ~ 45 minutes
Two days later the battery is at 12.2 volts
-- a 90 watt load (~ 8 A)(low beams) dropped the battery to 11.7 volts
-- fiddling with the headlights for under 5 minutes dropped the estimated SoC by 10%
--- So from a short test the battery capacity is ~ 8*5/6 = 7 Ah. Out of perhaps 35 - 40 Ah when new

Looks like you have an old, weak and worn out aux battery and probably time to be looking for a replacement soon.
 
nlspace said:
SageBrush said:
For anyone interested in my battery evaluation games:
All battery readings are from a battery tester doodad I have connected to the battery all the time. I read the voltage and "SoC" from a bluetooth connected app that also logs voltage readings every couple of minutes.
I charged the battery to 'full' on 12/30 -- 12.6 volts
The next day the car was driven ~ 45 minutes
Two days later the battery is at 12.2 volts
-- a 90 watt load (~ 8 A)(low beams) dropped the battery to 11.7 volts
-- fiddling with the headlights for under 5 minutes dropped the estimated SoC by 10%
--- So from a short test the battery capacity is ~ 8*5/6 = 7 Ah. Out of perhaps 35 - 40 Ah when new

Looks like you have an old, weak and worn out aux battery and probably time to be looking for a replacement soon.
My conclusion as well.

I charged the battery to 'full' -- 12.7v and headed to Autozone. Their device reported a drop in voltage to 12.6v with a 250 A load. I asked the woman to test again and the same result came back. So now I am unsure, and decided to buy the bits I needed for a load test. I took Jerry's excellent advice and bought a 12v lightbulb at Walmart (55 watt, H7) for $10 and a $5 H7 connector at Autozone. Flush with anticipated adventure I splurged $4 on a pair of alligator clip wires.

To my pleasant surprise the rig lighted up and I was ready to declare success when smoke started to come out of a wire. I think the wires touched each other and shorted so now I have to buy a new set of alligator wires and try again.

Question though: I attached one wire to the negative terminal of the 12v battery. Should I have connected it to the car as ground instead ?
 
It wouldn't matter where you attach the return, either to battery terminal or chassis.

what size wires (gauge and length) are used in the alligator clip kit? The initial inrush current will be somewhat higher for a brief period until the filament heats up, but then you will be passing about 4.5 A for a 55W lamp. So any high resistance junction, solder or wire crimp in the clip assembly could be getting quite warm.

Can you check the fluid level of the cells in the battery? What is the age?
 
Yes some cheap alligator clip leads use 22 gauge wire, which might not be enough for 4.5a, they are more for signal voltages or very low amperage use. Still shorting a battery out with most any clip leads could smoke the wire pretty quickly.
 
The alligator clip wires used the 14g hole on my wire stripper.
I'm reasonably sure I was the cause of the smoking affair

@nlspace, the battery is sealed

I appreciate everybody's help and advice
 
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