I bought an Ego 56V 21" mower non self propelled to replace a Honda self propelled of the same size, it uses a 56v 5ah pack (14S2P), it take me 40mins to mow the front and back lawns, that's after I do the edges with Ego multi tool where I can change the head for an edger, line trimmer, pole saw..., Then I finish and clean up with Ego blower, so say an hour all up by then the battery is just starting to dump.
I've had this mower and tools for 2 years plus, mower Blade is easy to keep sharp and to replace, no smell, no vibration and hence no numb hands, it's quiet where you can have a conversation with someone without yelling, the mower even has headlights so if it gets dark while mowing late you can see where you are going.
Battery take an hour to charge with the fast charger
I'll never go back to petrol powered, this mower is just as good as the Honda at half the price, Ego have a back pack for the batteries, hmmm, backup battery for the e-bike.