PetraTools HD4000
A 4-gallon sprayer with battery and charger that runs all day on a charge, for homeowners and small crews spraying large lawns or acreage.
Amazon $199.99$199.99
The PetraTools HD4000 is the better battery backpack sprayer overall, rated 3.9 to 3.2. The PetraTools HD4000 leads on value, features and runtime or airflow. The Milwaukee M18 Switch Tank wins on spray power. The PetraTools HD4000 costs $199.01 less ($199.99 vs $399).
Prices were last checked November 9, 2026. Product prices and availability are accurate as of that date and are subject to change; the price and availability shown on Amazon or the retailer's site at the time of purchase apply. As an Amazon Associate we earn from qualifying purchases.
Milwaukee M18 Switch Tank
A powerful 4-gallon sprayer for Milwaukee M18 owners, especially pros spraying harsh chemicals.
Amazon $399$399
Which should you buy?
- Choose the PetraTools HD4000 for value ($50 per gallon of tank ($199.99, 4 gal) vs $99.75 per gallon of tank ($399, 4 gal)), features (battery and charger included, adjustable pressure, 4 or more nozzles, gauge or control panel vs adjustable pressure) and runtime or airflow (50 tanks per charge (200 gal) vs 20 tanks per charge (80 gal) with a battery sold separately).
- Choose the Milwaukee M18 Switch Tank for spray power (up to 140 PSI vs up to 90 PSI).
Scores side by side
Each factor is scored 0-100 against the same fixed reference points for every 4 gallons and up battery backpack sprayer; a clear win is highlighted. How we rank explains each one.
| Factor weight | PetraTools HD4000 | Milwaukee M18 Switch Tank |
|---|---|---|
| Overall rating | 3.9/5 | 3.2/5 |
| Value 25% | 56 $50 per gallon of tank ($199.99, 4 gal) | 12 $99.75 per gallon of tank ($399, 4 gal) |
| Tank size 10% | 67 4 gal tank | 67 4 gal tank |
| Spray power 20% | 79 up to 90 PSI | 100 up to 140 PSI |
| Runtime or airflow 20% | 100 50 tanks per charge (200 gal) | 60 20 tanks per charge (80 gal) with a battery sold separately |
| Features 15% | 75 battery and charger included, adjustable pressure, 4 or more nozzles, gauge or control panel | 20 adjustable pressure |
| Warranty 10% | 0 warranty not published, scored as none | 50 3-year warranty |
Specifications
| PetraTools HD4000 | Milwaukee M18 Switch Tank | |
|---|---|---|
| Spraying | ||
| Tank | 4 gal | 4 gal |
| Max pressure | 90 PSI | 140 PSI |
| Max flow | - | 0.5 GPM |
| Nozzles included | 6 | - |
| Wand length | 34.5 in | - |
| Power | ||
| Battery | 12 V 8 Ah, included | 18 V, sold separately |
| Runtime per charge | 6 hours | - |
| Gallons per charge | 200 gal | 80 gal |
| Tanks per charge | 50 | 20 |
| Features | ||
| Adjustable pressure | Yes | Yes |
| Agitator | No | No |
| Gauge or control panel | Yes | No |
| Build | ||
| Warranty | - | 3 years |