I'm getting tired of replacing my AA batteries for my two speedlights. I never had any luck with rechargables in the past but now I noticed a new line of Eneloop Ni-MH batteries available. These must be a better quality battery, similar to what's used in DSLR cameras? Does anyone use these rechargeable batteries in their speedlights? Or, while I'm on the subject, does anyone measure the actual voltage of their standard, disposable batteries? What voltage is too low to bother with? We can't wait around too long for your speedlight to recycle during an event. Thanks!