Electronics that constantly draw low amounts of power — such as some wall clocks, headlamps, or bike lights — work better with disposable alkaline batteries
I use low discharge NiMH rechargables in all of my battery bike lights and they work great, they'll last for about 3 months of my usage (I run the taillights night or day), but I charge them all at the end of the month (I have 2 sets, so one set's on the bike and one set is charged and ready to swap out). I'm on the same set of Eneloops I bought 6 years ago. Every year or so I have my charger run a discharge test and they are still within about 90% of rated capacity.
I'd have thrown away 24 sets of disposable batteries in that timeframe (since I keep an extra set of batteries charged, so it's a ratio of 1:12). I paid ~2.50 each for the eneloops when I bought them, so cost wise it's been a good investment, works out to around 20 cents each so far (ignoring the cost of electricity)
It's getting harder to find non-rechargable bike lights, my main headlight uses a non-replacable LiIon battery.
I use low discharge NiMH rechargables in all of my battery bike lights and they work great, they'll last for about 3 months of my usage (I run the taillights night or day), but I charge them all at the end of the month (I have 2 sets, so one set's on the bike and one set is charged and ready to swap out). I'm on the same set of Eneloops I bought 6 years ago. Every year or so I have my charger run a discharge test and they are still within about 90% of rated capacity.
I'd have thrown away 24 sets of disposable batteries in that timeframe (since I keep an extra set of batteries charged, so it's a ratio of 1:12). I paid ~2.50 each for the eneloops when I bought them, so cost wise it's been a good investment, works out to around 20 cents each so far (ignoring the cost of electricity)
It's getting harder to find non-rechargable bike lights, my main headlight uses a non-replacable LiIon battery.