Emailed Zendure about this to get a definitive answser about cold weather. The response was "X6 is safe to use in your car, but this item doesn't have a temperature control function"
I wouldn't expect a configurable function that allows you to control the temperature.
I wouldn't expect it to be able to control its temperature.
I would expect it to stop charging below freezing.
I don't know what their statement means!
So is the main potential issue with using this in cold weather charging it at cold temps?
With modern lithium powerpacks, almost the only way to damage them, and potentially create a fire risk, is to charge them below freezing. Some have a low temperature cutoff which removes this risk completely, but not all do.
I would think that in those circumstances using a thermal cutoff of any kind would mean that the X6 would never get charged basically through all of winter.
Depends on where you keep your vehicle! In the UK, the interior of most vehicles almost never reaches freezing point. In some colder places the same is true because vehicles are kept in heated, or at least insulated garages.
And an external thermostat would only register the ambient temperature, not the temperature of the batteries (car's heat causes thermostat to turn on power, but batteries are still frozen).
Best to have the thermostat as close as possible to the battery, or better still inside it. But then it is unlikely that the car heaters will heat the battery up in time for it to start charging before the end of your journey!
Yes, this is a big problem, the answer is for the battery to include a heater, so that it can heat itself up to charging temperature, which may be what their response meant by "a temperature control function". I'm not sure it is actually worth having a heated battery though since most of our journeys are not long enough to heat the battery enough to start charging in time to get a useful charge.
Would something like
this TalentCell unit be a better option for year round use since it's a LiFePO4 battery like the Cellink Neo and others?
LiFePO4 batteries are not immune to problems caused by charging below freezing. They seem to be less likely to burst into flames, but they can certainly be damaged by fast charging at below freezing. We are now seeing quite a few Cellink batteries failing, possibly because they didn't have low temperature charging cutoffs.
The response was "X6 is safe to use in your car,...
That should be enough, although I would have liked them to add the words "below freezing", or "at all temperatures".
You could test it, put it in the freezer for a few hours, then plug it in to charge. If it takes several amps of current then it has no protection against cold charging. If it takes close to zero power then I will be happy to recommend it in future!