Newbie question on 62KWH battery warmer

[frontrangeleaf]

I really wish Nissan would clarify what Leaf+ owners can expect in very cold conditions.

I left ours out this week in very cold temps with about 45% charge, and trusted that it would behave in a reasonable manner given its SoC. I’m kind of tired of worrying about it.

It doesn’t get cold enough here for long enough to matter. We did see temps in the low single negative digits Fahrenheit overnight, with highs in the teens.

But I feel it’s unacceptable that the owners manual should be so ambiguously worded. It would be also unacceptable that the battery would only run whatever heating ability it has while plugged in AND at a reasonable charge level, if in fact that is the case. Reasonable charge level alone should suffice.

My sense is it might otherwise violate Magnusen Warranty Act terms, but I’m not a lawyer.

 

[knightmb]

It would be also unacceptable that the battery would only run whatever heating ability it has while plugged in AND at a reasonable charge level, if in fact that is the case. Reasonable charge level alone should suffice.

As far as we can tell, it will run independent of the EVSE connection. The issue is, if you leave the car out for days in sub zero temperatures, the battery will deplete itself to stay warm. At least with it plugged into the EVSE, it can draw that power to stay warm instead of depleting the battery charge. We know it does work that way, the manual is very badly worded, but I myself have been trying to figure out how the 62 kWh is staying warm without a battery heater installed. The theory has been some electronics in the battery case are just kept running to produce "waste" heat on purpose and that keeps the battery from freezing.

 

[DaveinOlyWA]

The Leaf is designed so that all accessory power draw that isn't 12 volt comes from the high voltage pack, with the pack getting charged whenever the EVSE is plugged in and a charge timer isn't constraining it from charging. The car's accessories can't ever draw power from the EVSE.

Thanks - but it's still not clear. Is the battery warmer an accessory? If the warmer can only be turned on with the normal charger plugged in, then it would draw from the charger and not the battery. Is the statement I quoted incorrect? It will not draw from the battery?

Asked another way, if it's -10F and it's not plugged in, will the warmer be used to keep the battery from becoming too cold to use?

Edit: From the OP: The Li-ion battery warmer does not operate if the normal charger is not connected to the vehicle.

The battery warmer is built into the battery in the 40 kWh packs and NOT for the 62 kWh packs. From what we have gathered here, there is some *software* mode warmer, which I'm still in the process of trying to figure out what that means. Since 2019, no one here has posted about battery damage from freezing (from our Canadian neighbors for example), so I am going to guess something does work but it's not clear exactly what it does. Reading the manual makes it seems like it must be plugged into an an EVSE to work, but it should work without it when it comes to keeping the battery warm during very cold times.

The plus pack has no heater? When did we discover this?

 

[frontrangeleaf]

The plus pack has no heater? When did we discover this?

Ummm, 2019?

The manual makes pretty clear, in the midst of some really horribly ambiguous sections, that there is no heater per se in the larger battery pack. I've read it a half-dozen times. I have no idea what they're trying to say.

Given all the controversy around Nissan choosing not to include a TMS in the Leaf, I'm imagining that they're not particularly motivated to clarify just how the bigger pack keeps itself warm in very cold temps. I haven't seen enterprising engineering types on the internet having examined this closely either, but neither have I looked much, as Denver is relatively mild.

It's a mystery. Anyone?

Folks in Canada are not reporting problems with their batteries freezing to my knowledge. It works somehow, apparently. Not exactly a "warm and fuzzy" though... Yet another dubious decision on Nissan's part, it would appear in the absence of evidence to the contrary. *Some* evidence either way would be preferable.

 

[LeftieBiker]

Maybe they generate heat by putting the packs to work collecting data from cell and WiFi signals in the vicinity, and transmitting it back to Nissan. When that's done, the packs are instructed to write Nissan owner's manuals.