That's why you use good rechargeable batteries (i.e. LSD NiMH), which are easier to replace and recycle when they're worn out than expensive, custom shaped, explosive Li-ion batteries

On my tourer/commuter I use a hub dynamo with connected lights (B&M Lumotec IQ Cyo R Senso Plus and B&M Toplight Line Plus) which are great to see and be seen. Recharging batteries with the hub is also possible, e.g. with the B&M E-Werk or the Zzing or ... connected to it.
On my other bikes I use LSD NiMH batteries in pretty normal bike lights. Unless you plan to use the front light every night (when in camp) they should last long enough to recharge them somewhere (save energy by running them in blinking mode whenever possible).
If planning to use the lights a lot, like in a Nordic winter, I'd definitely prefer hub dynamo powered lights.