Summary: .... maybe because it's first generation; (1) It's a complete battery hog in spite of A-L's claims for long life. AA's last a couple of hours at most. Get rechargeable batteries, but even then you may have problems (2) 9 volt power plug-in doesn't work. I Had to call A-L for a replacement (3) I bought some rechargeable high-power NiMH batteries at the suggestion of A-L customer support. It' still not enough power. The unit auto shuts-off after 3 minutes.