Security Indicator Light

[z0ner]

Is this light supposed to always blink when the car is locked or unlocked? I didn't notice it before, and I can't imagine Nissan would put a constant (albeit small) draw on the battery.

I've searched the forum, and manual but I haven't found the answer. The dealer thought it was standard and would only draw off the 12V.

 

[Lopton]

Mine blinks all the time.

I am assuming they use a red LED for it, and red LEDs use an very small amount of current, something like 20ma at ~2 V (going to geek out here, so that is 4mW (if my brain is function right), which would discharge the 24kwh pack in right around 70 years if my math is right. :ugeek: )

-Matt

 

[tps]

Mine blinks all the time.

I am assuming they use a red LED for it, and red LEDs use an very small amount of current, something like 20ma at ~2 V (going to geek out here, so that is 4mW (if my brain is function right), which would discharge the 24kwh pack in right around 70 years if my math is right. :ugeek: )

-Matt

Yes, but the LED is likely not driven by an efficient 12VDC/2VDC converter. There's probably a series resistor burning up the 10 VDC difference. Your original calculation is off by a factor of 10: 2 * 0.020 = 0.040, or 40 mW; if one includes the series resistor 12 * 0.020 = 0.240, or 240 mW. I've run into this in circuit designs where I have to use 1/4 watt series resistors instead of 1/10 watt...

Could be they're using a LED with multiple series elements to get higher efficiency and/or a driver with an active current source rather than a simple series resistor, both techniques I've seen.

 

[planet4ever]

Loptom's 4mW was obviously a typo. The 70 years is correct for 40mW. Of course it drops to "only" 11 years if you figure 240mW.

Ray

 

[rawhog]

What security light? :shock:

 

[Lopton]

ah ha but the LED blinks, so that off time must save some power to :lol: The light is a little red car with a key in it that flashes on the main dash console when the car is off, similar to the red led that most cars with alarm systems have that blink every couple seconds... a theft-deterrent I believe.

-Matt