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  • Home
  • Product Search
  • Benefits
    • Benefits
    • Testimonials
  • Discount Bundles
    • All Bundles
    • M4
    • M6
    • M4 + Agitator
    • M4 18-20V (DeWalt, Milwaukee, etc.)
    • M4 upgrade kits
      • Agitator upgrade kit
      • Battery upgrade kit
      • Electrical upgrade kit
    • M2
  • Parts & Accessories
    • New Products
    • Valve Handle Trigger
    • Batteries
    • Wands
    • Pumps
    • Nozzles
    • HYDRAULIC
      • WANDS (14ft telescoping, 4 boom, etc))
      • HOSE (15ft, Coiled, Standard, Elbow, etc)
      • NOZZLES (QR, Flexi, Fan, Cone, , Multinozzle, etc)
      • VALVES/PISTOLS
      • QUICK RELEASE/WASHERS/O-RINGS/ADAPTERS
      • Washers/O-rings
      • Quick Release
      • Adapters
    • ELECTRIC
      • Pumps
      • Switches
      • Batteries
    • STRUCTURAL
      • Lid
      • Filters
      • M4 Pockets and storage
      • Straps/Buckles
      • Base plate screws
      • Tanks
  • Videos
    • Videos
    • New Customer
      • Quick start
      • Overview of parts shipped with the M4 Backpack Sprayer
      • Nozzle kit Overview
      • Assembly and final inspection
      • My4sons Quality Care
      • Top 10 reasons why the MY4SONS M4 is rated #1 on amazon
      • M4: Charging and rotary switch use
      • How to prime the M4 Backpack Sprayer using A garden Hose
    • New For 2026
      • New For 2026
      • Monster Cart
    • Part/Accessories
      • 14 ft telescoping wand video
      • 14ft telescoping wand adapting to other sprayers
      • M4 New super wide XXL water Tight Lid Seal
      • Wide Lid Preview
      • Spray Pistol
    • Electric
      • New Wireless Remote Control for the M4!
      • 2021 Electrical Upgrade Kit
      • Battery and Multimeter
    • Troubleshooting
      • Quick Fix#1 no power, no voltmeter lights
      • Quick Fix #2 no power but voltmeter lights on
      • 5 step diagnostic checklist
      • M4: Charging and rotary switch use
      • Is my battery good?
      • Solving a collapsing tank
    • Maintenance
      • The best way to wire the M4
      • Securing Shoulder Strap anchor screw
      • Changing the red valve handle piston
      • Getting rid of leaks
      • How to prime the M4 Backpack Sprayer
    • Part Replacement
      • Replacing the pump
      • Replacing a broken pump neck
      • Replacing the red and rotary switches
  • About Us and FAQ
    • A Message From Our Founder
    • Assembly and final inspection
    • Customer Testimonials
    • Contact us
    • FAQ
Log in
    MY4SONS
    • Home
    • Product Search
    • Benefits
      • Benefits
      • Testimonials
    • Discount Bundles
      • All Bundles
      • M4
      • M6
      • M4 + Agitator
      • M4 18-20V (DeWalt, Milwaukee, etc.)
      • M4 upgrade kits
        • Agitator upgrade kit
        • Battery upgrade kit
        • Electrical upgrade kit
      • M2
    • Parts & Accessories
      • New Products
      • Valve Handle Trigger
      • Batteries
      • Wands
      • Pumps
      • Nozzles
      • HYDRAULIC
        • WANDS (14ft telescoping, 4 boom, etc))
        • HOSE (15ft, Coiled, Standard, Elbow, etc)
        • NOZZLES (QR, Flexi, Fan, Cone, , Multinozzle, etc)
        • VALVES/PISTOLS
        • QUICK RELEASE/WASHERS/O-RINGS/ADAPTERS
        • Washers/O-rings
        • Quick Release
        • Adapters
      • ELECTRIC
        • Pumps
        • Switches
        • Batteries
      • STRUCTURAL
        • Lid
        • Filters
        • M4 Pockets and storage
        • Straps/Buckles
        • Base plate screws
        • Tanks
    • Videos
      • Videos
      • New Customer
        • Quick start
        • Overview of parts shipped with the M4 Backpack Sprayer
        • Nozzle kit Overview
        • Assembly and final inspection
        • My4sons Quality Care
        • Top 10 reasons why the MY4SONS M4 is rated #1 on amazon
        • M4: Charging and rotary switch use
        • How to prime the M4 Backpack Sprayer using A garden Hose
      • New For 2026
        • New For 2026
        • Monster Cart
      • Part/Accessories
        • 14 ft telescoping wand video
        • 14ft telescoping wand adapting to other sprayers
        • M4 New super wide XXL water Tight Lid Seal
        • Wide Lid Preview
        • Spray Pistol
      • Electric
        • New Wireless Remote Control for the M4!
        • 2021 Electrical Upgrade Kit
        • Battery and Multimeter
      • Troubleshooting
        • Quick Fix#1 no power, no voltmeter lights
        • Quick Fix #2 no power but voltmeter lights on
        • 5 step diagnostic checklist
        • M4: Charging and rotary switch use
        • Is my battery good?
        • Solving a collapsing tank
      • Maintenance
        • The best way to wire the M4
        • Securing Shoulder Strap anchor screw
        • Changing the red valve handle piston
        • Getting rid of leaks
        • How to prime the M4 Backpack Sprayer
      • Part Replacement
        • Replacing the pump
        • Replacing a broken pump neck
        • Replacing the red and rotary switches
    • About Us and FAQ
      • A Message From Our Founder
      • Assembly and final inspection
      • Customer Testimonials
      • Contact us
      • FAQ
    Log in Cart
    • Sealed lead acid battery 12v 8ah

      Sealed lead acid battery 12v 8ah

      Sale

      Sealed lead acid battery 12v 8ah

      Regular price $ 29.99 USD
      Regular price $ 39.99 USD Sale price $ 29.99 USD
      Unit price /  per 
      Sale
    • Lithium Ion Battery 12 Volt 12 Ah with Round Or Square Charger

      Lithium Ion Battery 12 Volt 12 Ah with Round Or Square Charger

      Lithium Ion Battery 12 Volt 12 Ah with Round Or Square Charger

      Regular price $ 49.99 USD
      Regular price Sale price $ 49.99 USD
      Unit price /  per 
    • Battery Conversion Kit For Power Tool Batteries (Select One Option, Battery and Charger Not Included)

      Battery Conversion Kit For Power Tool Batteries (Select One Option, Battery and Charger Not Included)

      Battery Conversion Kit For Power Tool Batteries (Select One Option, Battery and Charger Not Included)

      Regular price $ 59.99 USD
      Regular price Sale price $ 59.99 USD
      Unit price /  per 
    • External Battery Charger

      External Battery Charger

      Sale

      External Battery Charger

      Regular price $ 14.99 USD
      Regular price $ 19.99 USD Sale price $ 14.99 USD
      Unit price /  per 
      Sale
    • CHARGING

      Automatic Battery Charger For Blue Tank M4(Doesn't Fit White Tank)

      Automatic Battery Charger For Blue Tank M4(Doesn't Fit White Tank)

      Regular price $ 14.99 USD
      Regular price Sale price $ 14.99 USD
      Unit price /  per 
    • External battery charger adapter w/alligator clips

      External battery charger adapter w/alligator clips

      External battery charger adapter w/alligator clips

      Regular price $ 3.49 USD
      Regular price Sale price $ 3.49 USD
      Unit price /  per 
    • Lithium Ion Battery 12 Volt 12 Ah Without Charger (MUST USE LITHIUM ION CHARGER)

      Lithium Ion Battery 12 Volt 12 Ah Without Charger (MUST USE LITHIUM ION CHARGER)

      Lithium Ion Battery 12 Volt 12 Ah Without Charger (MUST USE LITHIUM ION CHARGER)

      Regular price $ 39.99 USD
      Regular price Sale price $ 39.99 USD
      Unit price /  per 
    • M2 Replacement battery

      M2 Replacement battery

      M2 Replacement battery

      Regular price $ 19.99 USD
      Regular price Sale price $ 19.99 USD
      Unit price /  per 
    • 1
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    Final assembly and quality tested in the USA

    2 Year Warranty — 30 day returns for unused items minus the cost of shipping. / Patents Pending. / Please note that the M4 system is not compatible with muriatic acid.

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