I used to use Eneloops and there is nothing wrong with them, but I have since bought some white Ikea Ladda NiMH AA and AAA batteries. They work very well for me, a bit more capacity than the Eneloops. Now I only buy them.

The only disadvantage is that there are not that many Ikea stores, so hard to find unless you pay exhorbitant fee for shipping.
https://www.ikea.com/us/en/p/ladda-r...tery-70303876/
https://www.ikea.com/us/en/p/ladda-r...tery-90303880/

I specified the white ones because they used to sell some cheaper ones that were not low discharge, but the ones I do not recommend do not show up on a search anymore.

I use a couple different smart chargers.

Hi,
On one bike. I run a Edelux front, B&M Secula Plus Rear powered by a Shimano dyno hub DH-3n70. On another I run an Edelux front, Rene Herse rear (threaded into the seat tube) with a SON 28 hub.
Both are reliable and consistent, and as a back up taillight I run the PDW FenderBot. Front back up is any USB rechargeable.
I commute and ride in the rain, and find the beam shape and brightness perfect.
With the Edelux, I run the light in "on" mode, for daytime visibility in the city.
Longer range, carry a 10k Mh battery pack to recharge or a wire and plug. same as you'd use for your phone.
Also, the USB e-werk adaptors offer trickle charging off the hub, but check that the power required won't effect the lighting.