Batteries for Wolfeyes Cree R2 WC LED Drop-in?

[qballxx]

Hey all.. I'm kinda new here so go easy.

I have a Surefire 6p LED that I dropped a Wolfeyes Cree R2 WC LED Drop-in *Low VF in. I'm currently running C123 primaries in it. Are there other batteries that I can run in it to make it alittle more bright?

Thanks

 

[jbviau]

My understanding (and someone will surely correct me if I'm wrong) is that these drop-ins have regulated output, so using different cells within the acceptable voltage range will just affect total runtime, not brightness. Are you not impressed with the R2?