With that motivation, he decided he wanted to be an environmental engineer, and found himself in the agricultural and biological engineering program at Penn State University, where he focused on soils and water research.
Update april 2016: The top 3 best sold battery powered weed eaters are the: 1) Black & Decker LST136W. 2) GreenWorks 21332 G-MAX. 3) Worx WG175 MAX. As you can see 2 out of 3 are still going strong since 2014, namely the Black & Decker LST136W and the Worx WG175 MAX, see their reviews below.
IMHO the Xbox Brand (even though expensive) is one of the best or you can go with AA Lithium batteries as well. Duracell is another good brand to go with. Panasonic rechargeable are also great to use as well. Here is the link below. Amazon.com: Panasonic BK-3HCCA4BA eneloop pro AA High Capacity New Ni-MH Pre-Charged Rechargeable Batteries, 4 Pack: Electronics.