Cold weather experience Alde, Nautilus and Lithium battery

We recently spent a night in Wisdom Montana and it unexpectedly got down to 14 deg F. I was a bit concerned about the water system and the lithium battery but everything worked fine. The Alde system kept us warm and the water system did not freeze, even though it was below freezing most of the night. No busted fittings and the pump worked fine. 

I was also concerned about charging the lithium battery through the 7-pin connector as we started out. The Victron Smart Sense is programmed to disable solar charging at 32 deg F but there is no cutoff for the 7-pin (yet). However, considering that the truck will only provide about 5 amps or so, I decided to hook up and go. I know the common thought is to not charge lithium batteries if the temp is below freezing, but if you dig deeper most manufacturers say you can charge at a slow rate, like 0.1C, or 10% of rated capacity. We have a 100 ahr battery, so theoretically we could charge at 10 amps without damage. 

I wouldn’t want to make a habit of this, but if the temp drops below freezing we seem to be fine at least for a while. I’m not sure how this might compare with other models and years but our 2021 320S Boondock handled the conditions fine. 
2021 320S BD
2017 F-150
Coeur d'Alene, Idaho

Comments

  • Grumpy_GGrumpy_G Member Posts: 576
    With the trailer heated and the newer models having the underside covered a brief cold spell does not cause problems. If multiple days never get above freezing that might be a different story.

    The basic rule not to charge LiFePo batteries below freezing is still valid but low temperature charging protection has become almost a standard feature nowadays. One thing that works in your favor is that the batteries generate heat when discharging so the cell temperature might still have been above freezing when you connected the tow vehicle.
  • pthomas745pthomas745 Moderator Posts: 4,114
    It is the battery itself....inside the battery...that has to be below freezing before damage occurs from charging.  The air temperature or wind chill has nothing to do with this.  Maybe at 14 degrees, if your battery is outside in the tub, the low temp charging circuit would kick in.  Between the Smart Sense the batteries low temp charging protection you were probably well covered.  You don't say what battery you have....when I bought my lithium in early 2022 there were plenty of models without "low temp charging" circuits, and since I rarely get anywhere close to 32F, I purchased a battery without it.  So, you might want to look into that.
    If your 2021 still has a "regular" toilet and low point drains, the main issue with extremely cold weather like that would be the waste gate valves hanging out the front of the trailer.  The Alde can provide no protection for them, since they are well out side the trailer.

    2017 Outback
    Towed by 2014 Touareg TDi
  • WayneWWayneW Member Posts: 220
    I have an AmpereTime (now LiTime) battery without the cold charging cutoff. It’s several years old and that feature wasn’t as widely available as it is now. The battery and Smart Sense sensor are in the front tub in an insulated box that I built.  The sensor was reading -4 C (25 F) in the morning and I figured the actual cell temp in the battery was perhaps a few degrees above that. I knew the Smart Sense had disabled the rooftop solar because it is networked with the Victron controller but the 7-pin would still provide some juice. I intend to install a switch in the 7-pin charging wire, probably on the trailer side, so I can disable that if needed. My previous truck had a fuse I could pull but the 2017 F150 is too smart for that!  This was the last day of our 18 day trip so I figured, worst case, I’d damage the battery and then buy a newer model with the cold temp charging cutoff.  We often camp in below freezing weather so it would be a beneficial feature to have.

    I have the cassette toilet so the only really exposed plumbing fixtures are the low point drains in the Nautilus box. 

    2021 320S BD
    2017 F-150
    Coeur d'Alene, Idaho
  • pthomas745pthomas745 Moderator Posts: 4,114
    @WayneW sounds like your battery was well prepared even without low temp protection.
    2017 Outback
    Towed by 2014 Touareg TDi
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