Originally Posted by Monroe74
Thank you for your cost analysis but I was looking for real world experience.
I too am curious about this. The cost analysis route is interesting, but seems far lacking. For one thing, I would be impressed if you could keep your string trimmer engine running for 3 hours every day. But with an electric, if your finger isn't on the trigger, you're not using battery. There is no cost to idle. So 2 hours is a more realistic amount, but I suspect that it is even less than that (depending on the site).
Now you're back to 4 batteries. And should get at least 2 years of life from them.
Here's a simpler way of looking at it though. Forget how many batteries you need on-hand. That just confuses things.
With 45 minutes of run-time and 500 charges, that's 375 hours of operation for each battery. Accounting for idle time, let's say that's the same as 500 hours of gasoline operation. Assuming you burn a quart an hour (and I freely admit I pulled this number out of my butt), that's 125 gallons of gasoline you burned (probably with the added cost of 2-cycle oil), vs an almost negligible electrical cost of charging the batteries.
Ok, so there is a pretty high up-front cost, but the savings look like they can be real.
Makes even more sense, when you realize that 500 hours of engine time on a 2-cycle engine without any repairs is optimistic.
But all this thinking makes me want to hear some real world cases all the more.