There is one thing though with these batteries (eneloops) that you have to keep in mind. Use smart chargers that prevents over or under charging. I had an issue once where i had charged several eneloops on different chargers (not smart) and one of my strobes stopped functioning. After trying to figure this out for a while a pro-underwater photographer pointed out that if the batteries used were not all equally charged there can be an issue.
That maybe what happened in my case. I have two sets of eneloop pro, and a smart charger taking eight. Normally I pick all 8 fully charged out the charger and put them in the flashes. I was in a bit of a rush that morning, and may have put a discharged battery back into the flash. I'm running charge - discharge - charge cycles in the smart charger on all my eneloops this week, and I will do my best to "misuse" them on upcoming dives.
and was very disappointed. I JUST received my new enloop batteries in the mail yesterday for use in my strobes. now i have to decide whether to use them. I get it, there are plenty who use them and it works great, so i should be fine. it would help me make up my mind if i knew 1) why enloops are thought to be the best for strobes, and 2) if all the alternatives that I could use have "potentially" the same problem.
As far as I know all batteries can generate gas, and you will probably not be safer with any other brand. Underwater photographers use eneloop due to their good performance. I will continue to use mine, with no worries. Statistically, this is extremely rare.
Hydrogen generation can happen, however very rarely. Of all batteries I have used I was really surprised it happened with an eneloop, and also my newest set - 4 months old. No problems whatsoever with previous sets. I've done a charge - discharge - charge cycle in the charger, and it seems fully charged. Will try them again.