akg1486 wrote:We have learned one thing, though: not only must the batteries be warmer than 0 degrees Celsius when charging (which we knew), they have to be warmer than 0 degrees at all times. We have a non-heated hangar, so we're trying out wrapping the cowling and the batteries behind the pilot in electric blankets. That method seems to keep the batteries ten degrees warmer than ambient temperature. We haven't (yet!) had any nights colder than minus ten, but that will happen. We'll see how the batteries can manage that.
As a Tesla owner this is interesting! We have no info on sub-zero effects other than charge rate and range are both reduced with low ambient temperatures. In fact Norway was one of the very early markets for EVs.
What is it about the Pipistrel BMS that makes them suggest this? Incidentally we find a range reduction of something like 20% when below about 10C so keeping the battery warm is good!!
When it's all up and running I would love to have a flight
We who are not deeply involved in the technical discussions with the supplier are asking ourselves more or less the same question: batteries in Tesla and other cars seem to be more resilient to cold temperature. As you say, Tesla is sold in Norway; in fact it's the best selling model car. And electric cars are popular in Sweden too, where it's also pretty cold.
I don't have a Tesla, but perhaps it uses some of its battery power to keep itself reasonably warm?
I've taken the CBT training on Pipistrel's web site for the Alpha Electro, which is the previous, non-certified, version. That training said that it was important to only charge above zero degrees. I don't think they compared with batteries in cars.
Another thing about the batteries that we know, and I may have mentioned that in an earlier post, is that Pipistrel won't take every single new battery generation. The reason is that new batteries require new certification of the whole aircraft. So every single improvement made in the battery industry won't be immediately available to Pipistrel Velis pilots and owners.
Autocorrect is so frustrating. It's always making me say things I didn't Nintendo.