alozzy wrote: ↑Tue Jan 18, 2022 5:10 pm
I agree that I would be leery of pack degradation, but Dala seems to think that's not an issue based on a comment he made in another thread. Hopefully he can weigh in on this...
I think he is referencing the much larger size of the 40, 62 packs in relation to the load that causes degradation overall. For example, just for simple math reasons, say we have the 24 pack and it's safe discharge limit is 80 kW. If driving down a long country road only needs 20 kW to maintain good cruising speed for example, then you are loading the pack down at about 20/80 = 25% of it's rated power. As with all battery technology in existence as far as I know, the higher the load level against it's rated output, the quicker you deplete the capacity until empty. Basically diminishing returns the more power your draw as it gets wasted as heat. If you apply the same logic to a 62 pack, which is limited to 160 kW, using the same number of 20 kW to maintain good cruising speed, you are loading the pack down to 20/160 = 12.5% of it's rated power. So if those two Leaf are driving the same route at the same power usage, the 24 Leaf is technically going to experience more degradation than the 62 Leaf. Basically, one battery (24) and is working harder than the other (62) battery, even though they are both doing the same thing.
Apply that to home power or grid power sell back, say you are only using 10 kW with a brand new (24) battery. So it's roughly 10/80 = 12.5% of it's rated power output. Nothing wrong with that, but if you compared it to a (40) or (62) battery, they are working at around (10 / 110 & 10 / 160) or 9% and 6.25% respectively on power output. Not only are they doing the same thing at less effort, they are also newer technology batteries that seem to be doing better cycle life and capacity wise verse the original (24) technology.
All that math means the (24) packs will use "more" cycles to do what you want verse the other (40) and (62) packs because they have higher capacity and that means it takes more to "cycle" them in the grand scheme of things. You will be getting twice or triple the cycle life in this setup verse the original (24) battery.