find me a front light please.

[drossall]

Hope Vision One may come close.

JohnW of this parish speaks highly of it (possibly an earlier model) and IIRC has hinted that the AAs are in a removable battery pack, allowing you to carry a pre-charged set in their own pack ready to swap over.

Yes, I'm impressed with mine. The AAs are in a pack, though I haven't tried to buy a spare. Battery life is very good, and several levels of lighting so you can control how fast you run them down.

As the OP says, protection against battery failure because you just replace the AAs when they reach end of life.

[Roadster]

I won't post an eye-roll emoticon

I wouldn't have done if Squeaker hadn't - he started it!
As a relative newcomer here, I'd got the impression that use of the "Rolling Eyes" emoticon is more or less de rigeur when posting on this forum, so often does it appear. I applaud your restraint and hereby renounce its use myself.

[Gattonero]

I like Exposure lights - they do some seriously bright models and have very good battery life. They are quite pricey but the ones I have have lasted me very well and still going strong. The only point they don't match what you are looking for is that the battery pack is not removable. Given how long the lights can run for this si not likely to be a problem most of the time, if it is, they also sell piggy back battery packs that you can plug into the charging port if needed.

We're talking of Ferrari of bike lights here.
By far, the most bright and light, very durable as well (all machined alluminium).

I think that on next winter I'll pull the trigger on their Sirius: it packs a 3000mAh battery with 500 lumens in a small package that is less than 100gr.
Plus has side visibility and a good beam pattern. Can't see any other light of such size coming closer in performance.