I've had a 56 volt EGO for the past 3 or 4 years and it's still going strong.
I get 45-50 minutes run time using the 4.0Ah battery, which is just enough time to do my lawns.
There's been the odd occasion when the battery's run out before I've finished, but that's because I'd let the lawns get a bit long and/or it was damp.
I've also got the matching blower, line trimmer, hedge trimmer, and a 2.5Ah battery, so I just switch it over if I run out of charge.
I'd never go back to petrol or corded garden tools.