I haven't tried the Sanyos in my Optotronics 5mW pointer. I have tried the Energizers though and they didn't work very well. I talked to Jack and he said rechargables in general don't work very good with them. The Energizer lithiums work great though.freshert said:Sadly eneloops don't work well in my optotronics 30mw pen laser. Energizer rechargeable batteries work really well though.