I think he is causing even more confusion with this video in saying that the cycle life is usaly rated at dod of 80% every LFP cell I have looked up it is rated at 100% depth of discharge and after the 2500 to 4000 cycles (depending on the battery manufacture) it is still guarenteed to have 80% of the original capacity left , unlike lead asid batteries which normaly are done when the cycle life is over.
then theres the fact you have found another store video which is nothing but a guy trying to make himself sound smart and honest by misleading so he can sell you more batteries than you need claiming 80% capacity.....
