I've gotten away from Battery lights, nowadays Hub dynamos dont have an amp hour capacity problem,

But, being a tinkerer, when I did , need long running battery lights,
I built up a 5 D CELL battery pack to have see by lights .. It's the amp draw for a number of hours situation .
and C and D cells have more than AA..

newer LEDs are more miserly in current draw , and if this is a be seen, urban,

rather than dark rural road see by, light, then the flashing modes extend the battery life ..

get 2 chargers, have 1 at work so as to top off the battery charge, have some spare charged batteries .
on hand/in pocket.

if you got a Cubicle job, then USB rechargeable lights will be able to be recharged

as you key stroke your little fingers to the bone.

another Issue [in MN] is the cold battery is not functioning as good as a warm battery..
if you have a long cord for a battery pack inside your coat, then, that will be better than one on your handlebars .

or down on your forks ..

others tout brands of things they bought , they will chime in now..