Anker, producer of a lot of your favorite charging gear, has its own line of flashlights now, and you can get one for an all-time low $8 right now with promo code 24WL5MJO.
The entry-level LC40 model is IP65 dust and water resistant, but actually doesn’t include a rechargeable battery. However, you can run it on three AAAs or a single rechargeable 18650 battery, which are cheap and easy to find.