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Internet # 312763395

Model # 2820-20ps-48-11-1850

M18 18-Volt 4 Gal. Lithium-Ion Cordless Switch Tank Backpack Pesticide Sprayer with M18 5.0 Ah Battery

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  • Interchangeable Tanks, No Manual Pumping
  • Includes M18 18-Volt XC Extended Capacity Battery Pack 5.0Ah
  • Part of the M18 System, featuring over 250+ tools
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Product Details

About This Product

The Milwaukee M18 SWITCH TANK 4 Gal. Backpack Sprayer delivers the industry's first interchangeable tank design with no manual pumping. Designed to meet the needs of professional landscape maintenance, the battery-powered backpack sprayer provides users with instant, constant and adjustable pressure up to 120 psi and a 25 ft. spray distance. The 5-mode pressure adjustment knob adjusts the pressure between 20 psi to 120 psi, providing users with the capability to complete a wide range of applications. The 4 Gal. Sprayer Tank Assembly features a dual diaphragm pump for longer pump life and Viton seals for increased durability against harsh chemicals. The sprayer tank has a wide mouth opening for easier pouring and a strainer that filters debris from getting into the tank. The backpack frame includes wide straps providing users with added comfort during extended spraying applications and a handle for convenient transport and storage. The Milwaukee M18 REDLITHIUM XC 5.0 Ah Battery Pack delivers up to 2.5X more runtime, 20% more power and 2X more recharges than standard lithium-ion batteries. The lithium-ion battery pack features superior pack construction, electronics and performance providing users more work per charge and more work over pack life than any battery on the market.


  • Instant, constant and adjustable pressure for ultimate control
  • Up to 120 psi and 25 ft. spray distance
  • Run-time: up to 12 tanks per charge with M18 REDLITHIUM XC3.0 battery
  • Critical seals: Viton for increased durability against chemicals
  • Dual diaphragm pump: for longer pump life
  • Wide mouth opening and strainer: for easier, debris free pouring
  • Wide straps for comfort during extended duty cycles
  • Transport handle for convenient transport and storage
  • Includes: M18 SWITCH TANK powered base, switch tank 4 Gal. sprayer tank assembly, stainless steel wand, adjustable nozzle, fan nozzle, angled nozzle adaptor and M18 XC 5.0 battery (48-11-1850)
  • RedLINK intelligence: provides optimized performance and overload protection using total system communication between tool, battery and charger
  • Best-in-class construction: offers long-lasting performance and durability
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Product Information

Internet # 312763395

Model # 2820-20ps-48-11-1850

Additional Resources

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From the Manufacturer


Dimensions: H 21.75 in, W 13 in, D 10 in


Hose length (in.)48 inProduct Depth (in.)10 in
Product Height (in.)21.75 inProduct Length (in.)10 in
Product Width (in.)13 in


Adjustable spray tipYesApplicator typeSprayer/Mister
Battery Amp Hours5 AhBattery/Charger(1) 5 Ah Battery Included
Capacity (gallons)4Charger IncludedCharger Not Included
Compatible WithChemical, Grass Killer, Weed KillerIncludesSprayer Only
Number of Tanks1Number of Total Batteries Included1
Returnable90-DayShoulder strapYes
Sprayer FeaturesAdjustable Spray Tip, Backpack, Shoulder StrapSprayer/mister typeBackpack
Tank MaterialHDPE (High Density Polyethylene)

Questions & Answers

Q:Can I carry the M18 red lithium battery on a commercial airplane?
by|Jan 22, 2024
2 Answers
Answer This Question

A:  As long as it is in the carry on, in cabin location. Do not place it in your checked baggage.

by|Feb 10, 2024
    1 found this answer helpful

    A:  The 5.0 yes. 6.0 and larger you need airline approval.

    by|Mar 1, 2024
      Q:Can I tracked ?
      by|Dec 29, 2023
      0 Answer
      Answer This Question
      Q:Is it compatible with Milwaukee 0622-20?
      by|Dec 14, 2023
      1 Answer
      Answer This Question

      A:  I'm not sure what that number represents, because there are a few numbers missing. However, if this is a Milwaukee M18 tool, then yes, these batteries will fit in and power any M18 tool.

      by|Jan 31, 2024
        1 found this answer helpful
        Q:I am very Pro Milwaukee as far as supporting the brand and happily have over $10,000. In tools that I use without issue, except the sprayer, I bought one last fall used it 2X then stored it in a heated garage for winter, got it out this year & it leaks
        by|Nov 3, 2023
        1 Answer
        Answer This Question

        A:  We suggest visiting your nearest authorized service center. They can look at your tool and assist you with a warranty claim. You can locate the closest center by visiting our Milwaukee Tool website and then clicking on the "Support" tab, then "Find A Service Center". If you have any additional questions, please call at 1-800-SAWDUST from 8:00 am to 6:00 pm CT, Monday-Friday or email us at social.media@milwaukeetool.com. Thank you! - Milwaukee Tool, Social Team

        by|Nov 7, 2023
          Showing 1-4 of 107

          Customer Reviews

          4.5 out of 5
          • 4.5 out of 2,530 reviews
          • 74% recommend this product
          Filter by:
          Showing 1-10 of 2,530 reviews
          • Verified Purchase
          In no way did this sprayer come close to 3 stars.
          They don't even last 1 minute. Most come broken, leaking, etc. Even the Milwaukee service center in San Diego has to change locations every year to keep the angry customers at bay. Best bet, just get the 3 year warranty, buy about 10. That way you can just make 1 trip to Home Depot and return about 7 right off the bat. And careful what ya wear, clothes wise, this thing WILL leak all over you. YES!!I have run through about 10 of these. The last one I donated it to Milwaukee so they can figure out the chinese part.
          Response from Milwaukee ToolNov 22, 2023
          We'd like to hear more about your experience. Could you email us at social.media!@milwaukeetool.com? Thank you! - The Social Team
            • Verified Purchase
            Purchased early August still haven’t had recharge the battery
            • Verified Purchase
            1 found this review helpful
            Poor tank construction. Manufacturing issues
            This could be a great product. The sprayer part is pretty good. The tank stinks. Look around online and youll see that there are a lot of tank failures. Its a defect in the molding process and they all end up leaking in the same place
            Response from Milwaukee ToolJul 7, 2023
            Our team is sorry to hear about your experience with your Milwaukee M18 18-Volt 4 Gal. Lithium-Ion Cordless Switch Tank Backpack Pesticide Sprayer and the tank leaking. Could you send our team an email at Social.media@milwaukeetool.com, so we can assist? Thank you - Milwaukee Tool, Social Team
              • Recommended
              On my 3rd tank, now leaking.
              I purchased two sprayers in March of 2020. Two tanks, two motors. The backpack is fantastic due to the hip belt. Backpacking is one of my hobbies and I cannot understate the importance of a properly configured hip belt, with nearly all of the backpack weight carried on the hips, when carrying heavy backpacks. Everything about the sprayer is great, EXCEPT FOR THE TANKS. My two original tanks eventually leaked from cracks, a third I received from Milwaukee now leaks. This is a common issue.
              Response from Milwaukee ToolJun 26, 2023
              We are sorry to hear about this experience with a few of your Milwaukee M18 18-Volt 4 Gal. Lithium-Ion Cordless Switch Tank Backpack Pesticide Sprayers. Our team would like to learn more information such as the serial number of the unit. Could you send our team an email at Social.media@milwaukeetool.com, so we can assist? Thank you - Milwaukee Tool, Social Team
                2 found this review helpful
                3rd tank in a row leaked, Milwaukee contacted, management notified,...
                3rd tank in a row leaked, Milwaukee contacted, management notified, all three purchased online and returned
                • Verified Purchase
                4 found this review helpful
                It's an awesome piece of equipment but the only thing is for the free battery make sure you bring it up at the same time and the people there don't seem to know anything about
                • Verified Purchase
                • Recommended
                25 found this review helpful
                Tank leaks but can be fixed
                Bought a brand new one. Unsuprisingly the tank is leaking. I then spent ~ 40 min to fix it as I figured out it may require more time to get Milwaukee's replacement. Here is what I did: 1) remove screws on the tank's bottom to open the black base cover. There are four white plastic fittings under the cover. 2) Fill tank with some water to spot the leaking fitting (My unit leaks on fitting 1). Empty the tank 3) Unscrew the fitting by turning Part B counterclock wise while holding Part A in position . Yes, the two parts are seperated but water tight. 4) Add some layers of teflon tape to the thread ( I also added a thin layer of PTFE thread sealant) . 5) Screw the fitting back to position. 6) Refill the tank with water to check the leakage. 7) If no leakage, rotate Fitting 1&2's Part A to inward direction so that the whole back cover can be placed back Hope this helps
                  • Recommended
                  31 found this review helpful
                    10 found this review helpful
                    Showing 1-10 of 2,530 reviews

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