Is a corded electric string trimmer powerful enough for a typical yard?

For most suburban lots under about a quarter acre, yes. Verified-purchase reviewers across Amazon, Home Depot, Lowe's and Walmart consistently report that 5–6.5 amp corded models like the Black+Decker BESTA510 and BESTE620 handle weekly grass and light weeds without bogging down. Thick brush, ironweed, or anything woody is where reviewers say corded electrics — and most battery models — struggle.