I recently purchased a few GE battery powered "closet lights". These single tube fluorescents are powered by eight AA cells have have "STATELLITE F8T5D" 12' tubes. I diassembled one and soldered in a couple of lengths of leads to connect to my RV solar system. At 13.8v, the light only lasted about 4 hours of continus use. Needless to say, I was a disapointed. I have three more i'd love to use, but fear the same results. I did a test with 8 fresh (new) 1.5v AA's (a little over 12v), and they seem happy at 450ma draw. Can they really be THAT sensitive to 1.8v increase? BTW, they only $7 apiece.