Originally Posted by
Machdiamond
Good point on the 80% to 100% charge. The last 10% can take another hour. So let's say charge to 95% in an hour instead of 80% in 30 minutes.
We can't just say that because it can't happen - the last 20% (or more, depending on which sources you choose) is voltage-limited and so simply can't use high current. During this phase of the charge the current tapers off and the rate of charge drops accordingly. You can only "fast charge" for the part of the charge where the higher voltages needed to achieve the higher charge rate won't damage the cells. Fast charging is also very inefficient - you have to put more energy into the cell to increase the charging current, but you still get the same energy out. The snake-oilers of the Electric Vehicle Taliban never seem to mention this aspect.
Real life data (for example from this heavy fleet user
https://www.tesloop.com/blog/2018/8/...s-in-two-years) who charges typically to 95% and shows only 13% battery degradation after 300000 miles and, even more importantly, apparently showing no further degradation. And we are talking here about 5 year old battery technology, not the latest and greatest.
Automotive experience doesn't really read-across to aviation. Automotive cruise power demands are very small compared to the peak capability, so the batteries have an easy life. As the numbers in my previous posts show, the aviation power demand is much higher, and it's constant. This would work the cells much harder.
I am not sure why there is such a widespread negative misconception on reduced battery life and long charging time, I keep reading comments like yours but the reality is very different. I don't know, maybe this is coming from the public perception from cellphone batteries which are unfortunately incorporating programmed obsolescence.
Twaddle. My "conception" of battery degradation is based on properly conducted, peer-reviewed engineering studies. Whilst I wouldn't argue that Apple artificially mess with apparent battery life for commercial gain (because they are crooks - go figure) there are other phone manufacturers, and laptops, and power tools, and invalid carriages etc etc etc all of which show this degradation. I have removed the seemingly degraded battery from a cell phone and measured its capacity (both as-removed and after extensive battery conditioning) and personally confirmed that it bot only has less than 60% of its initial capacity, but it also suffers higher impedance (so its terminal voltage drops more under load).
But none of this is relevant to this discussion - I'm just using the data as provided by the project and asking if this really is a viable electric aeroplane.
PDR