The M4 with a built-in agitator, for anyone spraying powders or mixes that settle in the tank.
Amazon $299.99The My4Sons M4 Agitator is the better battery backpack sprayer overall, rated 3.7 to 3.0. The My4Sons M4 Agitator leads on runtime or airflow, features and spray power. The Chapin 63924 24V wins on value. The Chapin 63924 24V costs $60.99 less ($239 vs $299.99).
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.
A simple 4-gallon battery sprayer, made in the USA, for lawn weed and fertilizer jobs that need steady, moderate pressure.
Amazon $239Which should you buy?
- Choose the My4Sons M4 Agitator for runtime or airflow (50 tanks per charge (200 gal) vs 14.5 tanks per charge (58 gal)), features (battery and charger included, adjustable pressure, 4 or more nozzles, metal wand, agitator vs battery and charger included) and spray power (up to 80 PSI vs up to 60 PSI).
- Choose the Chapin 63924 24V for value ($59.75 per gallon of tank ($239, 4 gal) vs $75 per gallon of tank ($299.99, 4 gal)).
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 | My4Sons M4 Agitator | Chapin 63924 24V |
|---|---|---|
| Overall rating | 3.7/5 | 3.0/5 |
| Value 25% | 30 $75 per gallon of tank ($299.99, 4 gal) | 44 $59.75 per gallon of tank ($239, 4 gal) |
| Tank size 10% | 67 4 gal tank | 67 4 gal tank |
| Spray power 20% | 71 up to 80 PSI | 50 up to 60 PSI |
| Runtime or airflow 20% | 100 50 tanks per charge (200 gal) | 46 14.5 tanks per charge (58 gal) |
| Features 15% | 90 battery and charger included, adjustable pressure, 4 or more nozzles, metal wand, agitator | 30 battery and charger included |
| Warranty 10% | 0 warranty not published, scored as none | 25 2-year warranty |
Specifications
| My4Sons M4 Agitator | Chapin 63924 24V | |
|---|---|---|
| Spraying | ||
| Tank | 4 gal | 4 gal |
| Max pressure | 80 PSI | 60 PSI |
| Max flow | - | 0.5 GPM |
| Nozzles included | 9 | 3 |
| Wand length | 48 in | 20 in |
| Hose length | 60 in | 48 in |
| Power | ||
| Battery | 12 V 8 Ah, included | 24 V, included |
| Runtime per charge | 6 hours | 2 hours |
| Gallons per charge | 200 gal | 58 gal |
| Tanks per charge | 50 | 14.5 |
| Features | ||
| Adjustable pressure | Yes | - |
| Metal wand | Yes | No |
| Agitator | Yes | No |
| Gauge or control panel | No | No |
| Build | ||
| Warranty | - | 2 years |
