I don't have the largest back yard.. maybe 50'x30', or so.. With the VERY small weed eater I can mow the entire backyard on one battery charge, which is pretty impressive.. The hedge trimmer probably uses the most juice and I can easily trim ALL our hedges on one battery, with plenty to spare..
I have three tools: weed eater, hedge trimmer, and blower.. So, I got a battery with each tool, so I have three batteries and two charger thingies.. At most, doing the entire property I'll use up 2 batteries.. so, I always have one charged and ready to go.. if you run them out completely, they probably take about 2 hours to recharge, but, so far I've never had to wait on a charge.. You can get extra batteries, as well.. I think they're $30, or so..
If you have a large property, might ot be as efficient as mine are.. so far, for our property, its been perfect..
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