Buy rechargeable. The rechargeable batteries sold at Lidl and IKEA are excellent in my experience and quickly pay for themselves. Just start cycling single-use batteries out as they expire and it’s easier to keep track of who you’re supporting with your purchase when it’s a single annual purchase rather than something you buy every time you’re at the supermarket.

Not European, but Eneloop batteries are rechargable, last a long time and are more eco friendly than throwaway batteries.

If you have Alza in your country they also have their own brand, though those might be chinese made batteries

I saw a Project Farm video where they tested various AA batteries, alkaline and lithium.

One of the tests was how long each battery could run a fan with a constant energy draw and Varta Longlife got the worst score by far.

Those had a made in Indonesia label though, I don’t know if they have different plants in Germany with better specs under the same name.

Their website is really light on details about mAh[0], but Duracell are even worse[1]. I’ve found a comparison website, but no idea where its getting its sources[2].

Looks like VARTA is around 2400mAh and will last around 5-7 years, whereas Duracell is around 2700mAh and will last around 7-10 years. But let’s be realistic here, no battery in the world lasts more 2 years without needing to be switched out. Definitely not worth staying with Duracell.

0: https://www.varta-ag.com/en/consumer/product-categories/batteries/alkaline/longlife-max-power-aa
1: https://www.duracell.co.uk/product/duracell-optimum-aa/
2: https://www.batteryskills.com/aa-battery-comparison-chart/