Climate Control Solution - Gain Control of your Heater!

[Ingineer]

Here are the current scenarios where the heater can come on if the temperature demands it:

1. Climate control in full Auto
2. Climate control in Timer/Carwings mode
3. Rear defrost on

If the climate control is not in Auto (no LED lit), and the rear defrost is not on, the heater cannot run.

-Phil

That may not be 100% true. I swear I got heat last night when none of those were true.
*but*, I had been suffering with no heat, pressing various buttons trying to get things to come on so I may have stumbled on another scenario that enables the heat. I wish I could give more details. Unfortunately there is no light showing me when the heat is on, so I am feeling the vent to know when it is on. Next time around I will pull up the energy monitoring screen to watch while trying to find other ways to enable the heat.

By the way, does SOC affect heat? For instance, does the car disable cabin heat at very low SOC?

I think you misunderstand, those conditions I list are AFTER my heater control upgrade! The stock heat will come on whenever the interior temperature of the car is below the set temperature (the lowest you can set is 60), and the climate control is on, regardless of mode, A/C, auto, etc. This is the reason I developed this upgrade, as there is no way to full avoid heat unless you totally disable the climate control, which means you can't run the fan at all. This means your windows will quickly fog up, where just a little fresh air would prevent it.

-Phil

 

[qcar]

I am able to get just the fan to run without heat or air and in recirculate mode. This is no heat or Ac, just fan. Typically when the recirculate light is lit the ac or heat kicks in when you turn on the fan (and it switches to outside air). I am not sure what I am doing, but I get it back on recirculate and I am able to kill the AC and heat. Note however that when I did turn on the air on my way to work this morning (after driving for 2 hours in fan mode last night and 20 mins this morning), it was a bit smelly for a few minutes. I gather moisture must be building up somewhere in the system when I am running just the fan.

 

[DaveinOlyWA]

very nice Phil

 

[Ingineer]

I am able to get just the fan to run without heat or air and in recirculate mode. This is no heat or Ac, just fan. Typically when the recirculate light is lit the ac or heat kicks in when you turn on the fan (and it switches to outside air). I am not sure what I am doing, but I get it back on recirculate and I am able to kill the AC and heat. Note however that when I did turn on the air on my way to work this morning (after driving for 2 hours in fan mode last night and 20 mins this morning), it was a bit smelly for a few minutes. I gather moisture must be building up somewhere in the system when I am running just the fan.

The only way this will work is if your set your temp to 60, and the car is warmer than that.

-Phil

 

[TEG]

I think you misunderstand, those conditions I list are AFTER my heater control upgrade!

Yes, sorry - I thought you were talking pre-"upgrade".

I do find that my non-modified car seems to leave the heat off sometimes when I think it should be on.
So maybe the inverse of what I said it true - there may be some ways to keep the heat from going on that you didn't cover even without the mod. Or maybe my LEAF has some sort of defect. I was cold last night and started trying to get the heat to come on, and just turned the temp all the way up, and the fan all the way up, then turned off auto/AC, and set for recirc. I figured this would be the way to get most heat. But it just blew cold air for about 5 minutes before I gave up and started trying other things. I switched to defrost which seemed like it started up some heat, but then it also has the AC cooling it back down at the same time... Then when I went back to plain heat (no AC, no auto) I started to get decent heat from the vents. It is like I "kicked" it into action somehow.
As others are saying, there may be existing ways to convince it to run the fans without AC or heat running too.

Or maybe I had the heat on the whole time and it was just pre-heating something before it finally started to give heat so that first 5 minutes it was actually on?

I went looking through the car's manual last night and found it wasn't very detailed about how the climate system works.

I should probably go experiment with it some more before making more statements on the forum. Up until recently the weather had been so mild I hadn't been using the climate system (other than to just hit the "auto" button.), but this week I started trying to figure out how to seize full manual control...

I wouldn't have said anything except you started this topic to say how the system is deficient and needs your mod. I am not sure if I need the mod or not!

 

[Ingineer]

Yes, sorry - I thought you were talking pre-"upgrade".

I do find that my non-modified car seems to leave the heat off sometimes when I think it should be on.
So maybe the inverse of what I said it true - there may be some ways to keep the heat from going on that you didn't cover even without the mod. Or maybe my LEAF has some sort of defect. I was cold last night and started trying to get the heat to come on, and just turned the temp all the way up, and the fan all the way up, then turned off auto/AC, and set for recirc. I figured this would be the way to get most heat. But it just blew cold air for about 5 minutes before I gave up and started trying other things. I switched to defrost which seemed like it started up some heat, but then it also has the AC cooling it back down at the same time... Then when I went back to plain heat (no AC, no auto) I started to get decent heat from the vents. It is like I "kicked" it into action somehow.
As others are saying, there may be existing ways to convince it to run the fans without AC or heat running too.

Or maybe I had the heat on the whole time and it was just pre-heating something before it finally started to give heat so that first 5 minutes it was actually on?

I went looking through the car's manual last night and found it wasn't very detailed about how the climate system works.

I should probably go experiment with it some more before making more statements on the forum. Up until recently the weather had been so mild I hadn't been using the climate system (other than to just hit the "auto" button.), but this week I started trying to figure out how to seize full manual control...

I wouldn't have said anything except you started this topic to say how the system is deficient and needs your mod. I am not sure if I need the mod or not!

Do you have the current firmware upgrade? I've heard reports of issues like this on the older cars, but they supposedly have been fixed now.

The best way to tell if the heater is working is to pull up the energy screen and watch the climate control energy dial. As soon as you demand heat, you should see the dial start climbing within a few seconds. You will still HAVE NO HEAT until the fluid loop warms up. Since there is quite a bit of coolant mass in there, it can take a minute or 2 before the temp rises and the fan starts to blow warm air. As a "comfort" function, the system won't blow cold air.

-Phil

 

[GPowers]

Are firmwares upgrade a dealer only procedure?

 

[TEG]

Do you have the current firmware upgrade? I've heard reports of issues like this on the older cars, but they supposedly have been fixed now.

That might be it. Mine is an "early car" (VIN < 1000), and I have never brought it in for firmware updating.

 

[ebill3]

I need the mod.

Today was my first experience with needing a lot of defogging. I think it is criminal that in a $34 K car, I have to fiddle with a bunch of buttons and then cycle the defrost on and off in order to not suffer a severe range penalty. All I want to do is have the fan blow some air across my windshield, and that fan certainly will not draw 4.5 kW.

Bill

 

[gbarry42]

Screwdrivers are so 20th century. Send out the fix on a CD with the appropriate root kit

And don't call for Kaizen. Everything will grind to a halt and there will be a LEAF drought not seen since the Great Floor Mat shortage of 2011!

 

[Herm]

You will still HAVE NO HEAT until the fluid loop warms up. Since there is quite a bit of coolant mass in there, it can take a minute or 2 before the temp rises and the fan starts to blow warm air. As a "comfort" function, the system won't blow cold air.
-Phil

I recently read (probably here) that there is enough coolant mass to maintain the heat for about 15 minutes once you get it warmed up using the plug.

 

[saywatt]

I'm probably just a Neanderthal here, but is there a visible cabin temp sensor where one could hang a chemical hand warmer in front of to fake it into thinking the temp is above 60 degrees?

I am able to get just the fan to run without heat or air and in recirculate mode. This is no heat or Ac, just fan. Typically when the recirculate light is lit the ac or heat kicks in when you turn on the fan (and it switches to outside air). I am not sure what I am doing, but I get it back on recirculate and I am able to kill the AC and heat. Note however that when I did turn on the air on my way to work this morning (after driving for 2 hours in fan mode last night and 20 mins this morning), it was a bit smelly for a few minutes. I gather moisture must be building up somewhere in the system when I am running just the fan.

The only way this will work is if your set your temp to 60, and the car is warmer than that.

-Phil

 

[thankyouOB]

HT to all you guys and gals with the Leaf in a less temperate climate.
I have used the heater only once on the hiway, and twice to preheat the car when it was raining.
other than that, the sun seems to cover it.

I did put gloves in the car after the first cold trip, but havent used them yet.

 

[Ingineer]

I'm probably just a Neanderthal here, but is there a visible cabin temp sensor where one could hang a chemical hand warmer in front of to fake it into thinking the temp is above 60 degrees?

I imagine if you put 2 of them in at the start of each drive (there are 2 sensors), this would work. Of course, the cost and hassle of this is going to quickly get old.

-Phil

 

[downeykp]

Count me in also. If this works half as well as your evse mod I will be happy. Mahalo, Phil

 

[aqn]

I do find that my non-modified car seems to leave the heat off sometimes when I think it should be on.

Were you in D or in ECO? In ECO, the climate control does not run at full capacity (Nissan LEAF Service Manual, page HAC-23; also 2011 LEAF Owner's Manual, page 4-12).

 

[hgoudey]

I suppose it will throw codes, but if the heater is coupled by a liquid loop, it must be interlocked by the pump function (flow switch?). A crude fix to kill the heater without directly switching its high voltage DC supply would be to interrupt the low voltage DC to the heater circulation pump with a switch. Sorry for devolving from the more elegant solution, but that's what you get from the folks the who don't speak in the finer tongues of high level control systems. I'm just throwing this out as an observation. It probably isn't practical or advisable.

An amusing and potentially functional hack would be to re-purpose a 12VDC vapor compression or thermoelectric heat pump picnic cooler to provide modest directed heat and air for windshield defogging. It is an example of decidedly unsophisticated design that the Leaf climate control immediately jumps to the hammer of a 4kW heater when there are more subtle, yet still effective, means to mitigate the early stages of defog demand in modest climates.

I have another observation about the work-around approach of cycling climate control on and off to avoid heater use. I have been doing this a bit, but there is a potential flaw depending on the timing of the cycles. I would advise watching with the climate control power display to get a feeling for the appropriate cycle time. If you get useful service from the fan before the 4 kW heater load kicks in, that's great, but it is only ~10 seconds at a time? Once the heater comes on, it takes time to heat the liquid loop. During this time the air flow is not benefiting much from the added heat yet. If the climate control is cycled off at about the same time the liquid reaches temperature, most of those precious Li watt-hours are stuck in fluid that isn't going to do much useful heating work for you. At least it will probably start dissipating in less than optimal locations. I don't claim to have the exact answer for the best cycle time, but I suspect that very short and rather long cycles give better outcomes than somewhere in between. It's not that long cycles won't be a hit on range, but at least more of the battery energy consumed for heat will do useful heating for you. Still, it would be best to have a modest heat pump for lower demand defogging, as the 4kW liquid loop heater is a poor match to this need. It's kind of like having a household on-demand hot water heater serving a bathroom sink through 100 feet of pipe. Most of the hot water energy ends up sitting in the pipe and dissipated, after a modest end use demand (a few seconds of warm water at the tap).

 

[thankyouOB]

I sat in the car for 30 minutes last night with the car plugged in and charging, trying to get the heater to operate.
it remains a mystery.
the Ingineer trick of using the rear defroster did not seem to solve it.
maybe, I was too impatient.
but after 15 minutes, you would think it would work.
I admit though, I did not set it and leave it alone for 5 minutes.

 

[91040]

the Ingineer trick of using the rear defroster did not seem to solve it.
maybe, I was too impatient.

Ingineer's method only works with his modification.

 

[AP1]

Is his mod still alive and on the planning stages? Have my $ ready