seat warmer power consumption

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ytrottier

Member
Joined
Nov 8, 2015
Messages
11
What is the power draw of the seat warmers on the 2016 Nissan Leaf? A previous post ( http://www.mynissanleaf.com/viewtopic.php?t=10617 ) guessed 60W or below based on other cars, but I have the impression mine is using a lot more. Based on casual observation during my daily 200km commute, the high setting seems to consume an extra bar per hour, which would put the power draw over a kilowatt!

I've started keeping more careful data, and I admit it's hard to distinguish against the effects of wind, temperature, and charge history. But does anyone have more reliable information on this? What's the efficiency of the 360V-12V DC-DC conversion?
 
get an OBDII adapter, a phone or tablet, and leafspy app and you'll know your power draw for

Motor (drive motor)
Aux (lights, radio, etc)
Heater (just the heat pump or PTC heater for the forced air from the vents)
A/C (just the heat pump or AC unit for forced air from the vents)

You'll find with just the car running Aux will be 1 or 2. Add the seat heater on low, windshield wipers, headlights it might hit 3.

I've never used the seat heater on high but if you have this you'll see power draw change in digital numbers divided by enough categories to make it possible to isolate one or two items and then you can tell us how much your car is using.

Be sure to test in a warm garage and out in the cold. Test with climate control turned off, lights off, radio off, etcetera to be sure you don't have anything else cutting on when you check.

Maybe some of the power draw you think is coming from the seat heater is really the PTC heater (climate control) or the Pack heater (only if batttery pack hits -4F) kicking on at the same time you are using the seat heater?
 
I'm only running one seat warmer for the driver, the others for front and rear passengers are off. The climate control is always off. The coldest I've driven in was 7F, so the pack heater shouldn't be on yet.

I want an OBDII adapter, but can't splurge on toys right now. The numbers you give, what units are they in? Amps at 360V?

I've started writing down data from the percent battery charge on the dash, but I'll need two days with similar wind and temperature conditions for a good comparison.
 
ytrottier said:
I want an OBDII adapter, but can't splurge on toys right now. The numbers you give, what units are they in?

They vary

motor is 0 to 100 KW scale, 1 unit = 100W.

aux is 1 unit = 100W.

Heater is 1 unit = 250W. It goes off the top of the scale easier because the PTC heater uses so much power.

AC is 1 unit = 50W (edited)


I'm rereading the 140+ pages of the leafspy thread to confirm.

edit: official word is 100w, 100w, 250w, 50w from http://www.mynissanleaf.com/viewtopic.php?f=44&t=14285&start=1080#p412890
 
I understand the Leaf seat warmers are 12V, but I'm not sure why EVDRIVER points that out. I guess that does mean the seat power can't be much higher than 60W, otherwise some big cables would be showing. I'm still suspicious of the DC-DC efficiency though, since the 12V battery is charged from the 360V battery.

Thank you dhanson865!
 
From the schematic from my 2012 manual, it appears that ALL of the seat heaters work off of the same 15 amp fuse, so the most any individual heater could draw is about 45 watts (at the point of blowing the fuse). My wife's home heating pad draws 25 watts on MAX, so I doubt the Leaf's seat heaters draw much more than that.
 
Measured :) . 1.1-1.3Amps on Low and 2-2.5Amps on High. That means 35W is really max they can do, times two or three.
Rear seat is similar (but maybe not identical as there are two bottoms, no backheaters.

Average consumption on trips is much lower because it is idling when it has reached the max.
 
Thank you! Can't beat measurements. I've been taking more careful data using the battery percentages, and I think what was happening was that my regular commute just happened to be right on the edge of losing an extra bar. So yes, the seat heater can push me over the edge, but it's not using a full bar. But I'm still waiting for two identical wind/temp days to do a back-to-back comparison. I will post when I have that.

I'm still curious about the DC-DC converter efficiency if anyone knows that.
 
One bar is 21kWh / 12bars =1 750Wh. That is 1750Wh / 35W = 50h - 50 hours of one seat heater (or 25h of two seat heaters).
Most likely you use seat heater with colder weather. And that has much much more effect on range.

I know that 2011/2012 Leaf had dumb climate control panel that heated water even if climate was not blowing at all.
If it is chilly outside it will use some juice (maybe 100-500Wh) just because it is so dumb. Using any blower will result
in constant consumption. Is it the case? Does Climate consumption graph show any activity if blower is disabled?
 
But remember as soon as the car is in ready mode it is consuming somewhere between 200w and 400w with nothing else on, so you have to add any loads to that, not sure what it pulls in acc mode vs on, hopefully a LOT less, but it also isn't running the 12vdc charger all the time then either.
 
I've managed to collect data from three similar days. All these trips were along similar routes, with the same elevation change (+160m), same general direction (westward) and same weight. Climate control was always off for the whole trip.

Code:
Wind   SSW 24        SSW 24      S 24    km/h
Temp     +3           -3          +5     deg C
Speed   70.4          74.1       77.6    km/h average
seat     off          off        high    driver seat only, plus steering wheel.
Dist.   118.8        103.0       107.5   km
start     81           89         99     % charge
end       0            14         25     % charge
delta     81           75         74     % charge
d/chg    1.46         1.37       1.45    km/%charge

It's a 2016 model with a 30kWh battery, not the old 24. Supposing that 0 to 100% is 26kWh, 1.45 km/% works out to around 5.6 km/kWh, which is about what the dashboard computer gives. Energy economy is within 6% among all trips, which is within 3/4 of a bar. But most of that difference was probably just due to the lower temperature of the middle column.

My conclusion is the seat warmer doesn't make a difference. I probably got that impression from the reduced battery efficiency with dropping temperature. (And again, for those who didn't get it the first time, climate control was OFF. The 2016 has a heat pump, not a PTC heater, but it doesn't matter because it was off.
 
Actually Leafs with heat pumps do have PTC heaters. It is used much less and in above freezing weather almost not used at all.

Like I said 0,035kW each hour is not measurable :)
 
arnis said:
One bar is 21kWh / 12bars =1 750Wh.

The quote below shows how the bars are anything but even and I hope you'll see that you shouldn't use 1/12 for any sort of math related to them.

I'm not going to worry about duplicates at the cusp, I'm sure you aren't worried about the last tenth of a percent. Oh and there are two kinds of bars

capacity bars
100% to 85% = 12 bars (15%)
85% to 78.75% = 11 bars (6.25%)
78.75% to 72.5% = 10 bars (6.25%)
72.5% to 66.25% = 9 bars (6.25%)
66.25% to 60% = 8 bars (6.25%)
60% to 53.75% = 7 bars (6.25%)
53.75% to 47.5% = 6 bars (6.25%)
47.5% to 41.25% = 5 bars (6.25%)
41.25% to 35% = 4 bars (6.25%)
35% to 28.75% = 3 bars (6.25%)
28.75% to 22.5% = 2 bars (6.25%)
22.5% to 16.25% = 1 bar (6.25%)
16.25% to 0% = 0 bars (16.25%)



charge bars http://www.mynissanleaf.com/viewtopic.php?p=101293
100% to 91.5% = 12 bars (8.5%)
91.5% to 84% = 11 bars (7.5%)
84% to 77.9% = 10 bars (6.1%)
77.9% to 70.8% = 9 bars (7.1%)
70.8% to 66.2% = 8 bars (4.6%)
66.2% to 58% = 7 bars (8.2%)
58% to 50.9% = 6 bars (7.1%)
50.9% to 43.4% = 5 bars (7.5%)
43.4% to 36.3 = 4 bars (7.1%)
36.3% to 31.3% = 3 bars (5%)
31.3% to 26% = 2 bars (5.3%)
26% to 17.4% = 1 bar (8.6%)*
Low battery
Very low battery
Turtle

*see range chart and other threads for how dangerously quick you can drop from 1 bar to turtle. Don't rely on expected range at low states of charge.

and note the charge percents I gave were based on a 100% capacity battery all the charge bars get modified if the capacity is below 100%.

and I'd have to link to another thread to document why you shouldn't use 21 kWh and should instead use a higher number but for now I'll let that fraction be.
 
Thanks for the information and data! Is there a good place to read consolidated information on range and battery capacity, especially for the newer lizard battery? I'm commuting 210 km/day, in a situation where I have to be very careful about range. I modulate my speed and charging times down to the minute, collect lots of data, and adjust for temperature and wind to routinely arrive at destination with 2-3% charge.

I know the only long term solution is to instal a level 2 charger at home, and I have the hardware, but it may be months before I can arrange installation. (Don't ask. It's complicated.) Until then, I have to rely on smarts, discipline, and the weather getting warmer faster than my battery capacity fades. I've been doing this since November and never gotten the turtle mode, and with an early spring coming I'm optimistic I can make this work until my charger is installed.
 
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