Dinotte offers 2 AA powered taillights - the 140 and a 400. The 400 apparently has about the same output as the 140 in AA version, main difference is its mount, for ten bucks more. There is also a 400 Li-powered taillight, which is twice as bright as the 140. The web page is not very clear with this information.

http://store.dinottelighting.com/aa-...geable-c2.aspx