The Hudson Never Pump battery operated backpacks sprayer is one of the more popular battery powered sprayers.
It is used for pesticides and herbicides. Not for bleach or stain.
4 gallon backpack sprayer.
When I did a search on Amazon, I found a large number of positive ratings (hundreds).
It comes with four nozzles that you can interchange depending on your requirements:
1. Cone nozzle sprays on target to reduce waste.
2. Long-reach adjustable shower nozzle for spraying a fine mist to high places or drenching to penetrate gravel, bark, or thick weed patches with a herbicide.
3. Dual cone nozzle for quicker coverage of larger areas. Delivers a fine particle with a wide spray pattern to create a “fog”. For insect control and to get complete plant coverage above and below the plant canopy, this is the nozzle assembly of choice.
4. Fan nozzle for spraying flat surfaces. Perfect for spraying rows, cracks and crevices with less drift.