I have a small (4 x 6 3/4) Flambeau infinite divider system box that was mentioned in another CPF post that I keep in my work shoulder bag.
It contains in the first row- 1st compartment - 1 ARC 123 twistpack and a standard clickie pack with 2 AAA batteries on top, next compartment has a headstrap that will hold the LSH in 123 or AA config, a CMG Infinity or ARC AAA etc.
Second row - 1st compartment holds a Mag lens cap with bluw/white/red lens that will fit over the E2e, next compartment holds 3 AA and 1 AAA batteries, Next compartment holds an Infinity Ultra with battery.
Third row holds - 1st compartment 2 123 batteries, 2nd compartment holds an ARC 2 AA battery pack with 2 batteries in it with a lanyard on top and a ARC AAA with battery.
I place this box in a 7 x 8 inch zippered pouch that I got at home depot. Then add some type of 123 light (E2e, SL 1L/2L, PM6 etc in a country.com pouch and a 8 hour light stick. This gives several light sources and spare batteries.
AA batteries can be swaped between the LSH and Ultra. AAA between the ARC AAA in box and my EDC ARC AAA. 123 batteries swap between the LSH I EDC along with whatever 123 light is in the Country.com pouch.
Still room in the plastic box and the pouch to add stuff. Whole thing measures 7 X 8 inches. Keep in my work bag, if traveling or going camping just take it out and add to luggage.
About the only thing I add is an Eternalight X-Ray and Zipka +. When ARC LS4 comes out may put LSH in box, EDC the LS4 and leave the Eternalight in the van.
Of course in CPF tradition have other lights at home and in each vehicle!