On 5/10/2017 9:44 AM, Joerg wrote:

snip

Quote "4 rechargeable Ni-MH batteries, each 2100 mAh, no memory effect.
Charging time approx. 5 hours using provided charging unit. Power supply
by 4 non-rechargeable AA batteries possible".

For a lot of lights, the output is significantly less on primary cells.
Alkaline batteries have high internal resistance and can't provide the
current that NiMH AA batteries provide.

There are some good 4AA flashlights that could double as a bicycle light
but these are high-end lights and are expensive
https://www.fenixlighting.com/product/ld41-fenix-flashlight/.

There is this 3xAA bicycle specific light:
https://www.amazon.com/dp/B06X6FXCLN

Someone selling a NOS HL-EL530:
http://www.ebay.com/itm/Cateye-opticube-hl-el530-cycling-light-/172654249234

There's also the option of powering a light with an external battery
pack made up of AA cells rather than Li-Ion cells. For example,
http://www.herrmans.eu/start-english/products?familyId=2208 will run
on a 6-12V pack. But again, alkaline batteries will leave something to
be desired.