ORIGINAL: HuskerBoy
As a backup, I solder together 4 D cell alkaline batteries to give 1.5v with longer duration. Electrical tape together and with an 18" cord to a press-on plug adapter.
I don't even use a glow driver anymore. Four D cells soldered together like Huskerboy said lights off everything I fly for an entire summer. Glue them together with silicone before you solder, they are much easier to handle that way.
Rrragman