Extreme cold overnight hits Leaf Plus cold limits

[knightmb]

Thanks, I'll give it a try, it just seemed counterintuitive for energy savings to run both heat and A/C but your idea of being able to use recirc and in my case not bring in sub-zero temps may more than offset the A/C draw. Also I wonder if the A/C will even come on in my zero temps, sounds like you were in warmer temps....

Well basically, when it gets cold enough, the AC shuts off. If you leave the AC off, then the heat pump runs in reverse to produce heat, plus the element heat, uses more power. So using AC in the extreme cold is the same as having it turned off.

[PrairieLEAF]

It's common to combine A/C with defrosting (many vehicles do this automatically) so that the air blowing on the windows is extra dry. I presume the LEAF also runs the A/C compressor when requested, even in extreme cold. Then the resistance-heated air will blend in to satisfy temperature request. Warm (capable of absorbing more moisture) air-conditioned (dry) air is most effective for defogging.

I'll have to try Heat+A/C+Recirc...thanks!

[jjeff]

Thanks, I'll give it a try, it just seemed counterintuitive for energy savings to run both heat and A/C but your idea of being able to use recirc and in my case not bring in sub-zero temps may more than offset the A/C draw. Also I wonder if the A/C will even come on in my zero temps, sounds like you were in warmer temps....

Well basically, when it gets cold enough, the AC shuts off. If you leave the AC off, then the heat pump runs in reverse to produce heat, plus the element heat, uses more power. So using AC in the extreme cold is the same as having it turned off.

Yes for a heat pump Leaf that makes sense but unfortunately neither of my Leafs have a heat pump, the '12SL was before Nissan used a heat pump and the '13S like I believe all S models also lack the heat pump. If purchasing a new Leaf or even used I'd probably only look for one with a heat pump now that I know more about it. I purchased the '13 new but I wasn't educated in the heat pump and my saleslady knew even less of the Leaf than I did

[DougWantsALeaf]

My S+ does not have a heat pump. I do want to do the same test now with our SV+.

[DaveinOlyWA]

.....Battery temp.was interesting. I left with a high temp monitor reading of 51.5F, was at 52.5F at the halfway point, but was at 56.6F at the end (i did drive faster on way back), even at 12-15F outside temp battery warmed a little bit.

Thanks, I'll give it a try, it just seemed counterintuitive for energy savings to run both heat and A/C but your idea of being able to use recirc and in my case not bring in sub-zero temps may more than offset the A/C draw. Also I wonder if the A/C will even come on in my zero temps, sounds like you were in warmer temps....
I had a similar experience to you last weekend driving my '12 around when it was again around 0F. It started out with a battery temp of about 0F but quickly warmed up to 20F after only about 5 miles of mostly side streets with full heat, not full speed freeway driving. After less than 1 mile of driving I got the turtle, with I believe >60 SOC. It wasn't the full, crawl speed turtle you get with extremely low SOC but rather just limited me to 4? power bubbles(less than half) but was perfectly adequate to drive in. Note the turtle still stayed on my dash up to my halfway destination when the battery was 20F but after shopping for about an hour I started the Leaf, where I believe the battery was still around 20F and the turtle was no longer on. The power bubbles were still not full but just lacked the top 1/4 vs before when I only had the bottom 1/4 available.
I should note my '12 only has 8 battery bars so maybe that explains some of the odd behavior I'm having in extreme cold temps, looking at the histogram? of the battery cell voltages are all over the map

Need to dispel the ideology that AC will produce cold air somehow counteracting the heat. The A/C is only removing moisture and drier air is easier to heat up. I also found in milder temps, the AC on with vents closed helps to keep the windshield clear. The AC draws very little power with LEAF Spy registering power slightly less than half the time with the predominant draw being 50wh

[DougWantsALeaf]

Ok, was out to get some free NCTC DC juice (what else is there to do anyway) and tried with the SV+. When just running heat, (6-8F) outside, both heater and heat pump ran (heat pump showing up as AC draw). When you click on AC, the heat pump stops, and it just goes to the resistive heater. With recirculation on, it did seem like lower power draw with both heat and AC on, but too short of a test to know for sure.

Thankfully the DC charger is in a garage, so it was a much more pleasant 32F. 30 minute charging session only added 15F (44 to 59F) to the battery temp. Interesting that post charging,temps went up an additional 1/2 degree before starting to slide on way home.

[Kieran973]

Is there a consensus around cold weather best practices if the main goal is to minimize battery damage and/or long term battery degradation in the Leaf? I feel like I have a good grasp of how to navigate this with warm temperatures, but not with cold temps. Some basic questions that I don’t have clear answers to:

1. What ambient temperature lows can lead to battery damage or long term degradation?

2. What battery temperature lows can lead to battery damage or long term degradation?

3. Is there a battery temp threshold below which you should not DC fast charge?

4. Is there a battery temp threshold below which you should not AC charge?

[LeftieBiker]

As long as the battery stays within the temp range that Nissan specifies, there should be little or no damage from cold. I personally wouldn't DCFC with no temp bars showing.

[SageBrush]

Some basic question

Ambient is irrelevant

AC Vs DC is irrelevant; the question you are rightly asking about is current (Amps). I've seen my Tesla refuse to charge the pack at all when it is in the 20s F, but my pack is low Cobalt and as a result low temp intolerant.Tesla is able to heat up the pack before charging; I'm not sure about the LEAF. Does the LEAF BMS manage current in the cold ? I don't know, but if not then it is on you. It is my practice in the winter to charge only soon *after* a drive to avoid these possible issues.

I suggest you do NOT rely on what Nissan says is "OK." That is based on warranty considerations.

The presumed battery damage mechanism goes under the name of 'battery plating' or 'Li plating.'

[LeftieBiker]

I suggest you do NOT rely on what Nissan says is "OK." That is based on warranty considerations.

Which is exactly why I suggested that he use Nissan's CYA recommendations for temps. They are most likely a little conservative. I could be mistaken.