Yes, I did miss that. Sorry.

I do have 1 40v generic from Amazon. (link below) It's listed as 5ah and I get the same amount of time out of it as my 2 4ah batteries when blowing leaves.

https://www.amazon.com/gp/product/B093GGT7Y7/ref=ppx\_yo\_dt\_b\_search\_asin\_title?ie=UTF8&th=1