VAXMAY 4 Gallon Battery Backpack Sprayer, 100 PSI, Makita 18V Compatible

Description

If you are done fighting with hand pumps and spotty spray patterns, the VAXMAY 4 Gallon Battery Backpack Sprayer, 100 PSI, Makita 18V Compatible puts pro-level pressure and control on your back for faster, cleaner applications across lawns, ornamentals, and perimeter pest jobs. The core kit pairs a 4 gallon tank with an adjustable pump rated up to 100 PSI, a telescopic wand and a set of multi-pattern nozzles, and it is sold as Makita 18V-compatible for easy battery swaps, with many listings including a 2.6 amp hour pack and charger right in the box.

For operators who value uptime and consistency, several retailer pages also highlight a digital voltage display and low-voltage shutoff that help protect the pack and keep pressure stable, which is exactly what you want when laying down selective herbicides or barrier insecticides along foundations.

Key Customer Benefits

• Even coverage without hand-pumping: Battery drive keeps pressure steady so your spray pattern stays uniform, which helps you hit the label rate over the whole lawn or bed instead of leaving hot and cold spots. Extension guides explain that pressure and nozzle selection control droplet size and pattern, so a stable pump makes calibration easier and results more consistent.
• Real reach and control from 0 to 100 PSI: The VAXMAY listing specifies up to 100 PSI, and the included telescopic wand is shown extending for better access to fence lines, shrubs, and foundation cracks. Higher pressure can create finer droplets when you want foliar coverage, while lower pressure with the right tip helps reduce drift for soil-level herbicide work, so you can tune the spray to the task.
• Makita 18V compatible, with a battery and charger in the box: If you already run Makita 18V tools, compatibility means you can swap packs between jobs to keep working. Retail listings also show this sprayer commonly ships with a 2.6 amp hour battery and charger, so you can spray right away and add your own LXT packs later if you have them. Always confirm the exact bundle on the seller page.
• Five-nozzle kit covers weeds, ornamentals, and perimeter pests: The set typically includes fan and cone patterns for broadcast, spot, and foliage applications. University resources note that flat-fan tips excel for uniform broadcast herbicide work, while cone patterns are used when penetration or targeted coverage is needed. This flexibility lets one sprayer handle pre-emergent, post-emergent, and household perimeter jobs.
• Less fatigue and faster workflow than manual pumps: Compared with hand-pump backpacks, battery sprayers remove the constant stop-and-pump cycle, which saves time and keeps your pace steady. Pros and enthusiasts repeatedly call out constant pressure as the big advantage for even application and productivity on residential turf.
• Backpack precision for plant-by-plant care: A 4 gallon backpack gives you mobility for selective treatments around ornamentals, vegetable rows, and spotty weed outbreaks. Industry guidance highlights backpack sprayers for their ability to treat individual plants accurately with the right tip and pressure, which helps avoid off-target injury.

Product Description

What this sprayer is

The VAXMAY 4 Gallon Battery Backpack Sprayer, 100 PSI, Makita 18V Compatible is a four-gallon, battery-driven backpack unit designed for herbicides, insecticides, fungicides, foliar feeds, and light cleaning work around homes and landscapes. Retail listings specify Makita 18-volt compatibility, a digital voltage readout, and a protective low-voltage cutoff that shuts the pump down around 14 volts to help preserve batteries.

Several listings also show a bundled 2.6 amp-hour pack and a charger, so you can spray right out of the box even if you do not own Makita batteries yet. Materials on the spec cards include HDPE and polypropylene for the tank and body, with nylon in the fluid path. A telescopic wand extends to roughly 39 inches, and the kit ships with five spray tips for different patterns.

How it works

At the heart of the VAXMAY is an electric pump that you control with a pressure knob. The marketing spec calls out up to 100 pounds per square inch and a high-speed motor. That pressure range lets you dial in coarse droplets and low drift for soil-level herbicide passes or finer droplets for foliar coverage on ornamentals. The voltage display helps you keep an eye on charge status, and the low-voltage cutoff is there to reduce over-discharging, which is a common cause of premature battery wear. The headline runtime claim you will see on some pages is up to sixteen tanks on a charge, although real-world results depend heavily on pressure, tip size, and walking pace.

Nozzle choice is the second half of the equation. University and extension guidance is clear that flat-fan tips are the go-to for uniform broadcast herbicide work, while cone patterns are used when you need penetration or a tighter target area. Pressure affects both flow and droplet size, so raising pressure increases output but also tends to create more fine droplets that are easier for the wind to carry. That is why you adjust pressure in small steps and swap to a different nozzle size if you are more than about ten percent off your target delivery rate.

If you already run tools on the Makita LXT platform, the compatibility matters because you can rotate charged 18-volt packs through the sprayer and minimize downtime. As a reality check on battery expectations, Makita’s own 4-gallon cordless backpack sprayer quotes up to 165 gallons of output with a single 4.0 amp-hour 18-volt battery, which gives you a feel for what an 18-volt backpack system can do when paired with an efficient pump and tip. Use this as context rather than a promise, since exact runtime varies by model, nozzle, and pressure.

What makes it effective and different

Consistency is the reason pros switch from hand-pump backpacks to battery units. With a manual pump, pressure swings are constant, which means your application rate drifts unless you stop and pump every few steps. Field guides for sports turf and natural areas underline a simple rule: keep pressure constant during calibration and application, or your output will wander. A powered pump holds pressure steady, which helps you stay on label, reduce over- or under-application, and finish faster with less fatigue.

This particular VAXMAY setup layers in useful quality-of-life details for day-to-day routes. The long telescopic wand gives you reach into hedges, around fences, and under soffits without compromising your stance. The translucent tank markings make it easy to track how much mix you have left. The digital readout and cutoff are small touches that reduce guesswork and help protect your batteries. And because it is sold as Makita-compatible, you can standardize on one charging ecosystem if you already own the batteries.

A quick note on transparency. You will see different pressure numbers across storefronts for VAXMAY and near-identical sprayers. Some pages list the pump as adjustable to 100 pounds per square inch, while others list a top end closer to 75. If maximum pressure is critical for your use, verify the exact bundle and spec on the seller’s page before purchase.

Product Specifications

Category	Spec
Brand and model	VAXMAY, item model number XAR4000G.
Tank capacity	4 gallons, translucent body.
Pressure range	Adjustable pressure, seller pages list either up to 75 pounds per square inch or up to 100 pounds per square inch. Verify the exact bundle on the seller page.
Pump and controls	Electric pump with adjustable pressure knob, some listings note a 3,800 rpm high-speed motor.
Battery platform	Advertised as compatible with Makita 18-volt Lithium-ion packs. Many bundles also include a separate 21-volt battery so you can spray out of the box.
Battery and charger in box	Common bundles include a 2.5 to 2.6 amp hour battery and a charger. Charger input is listed as 110 to 240 volts.
Claimed run time	Up to 4 hours per charge and up to 18 tanks, which will vary based on pressure and nozzle size.
Wand and hose	Telescopic spray wand included, hose length listed as about 39.3 inches.
Nozzle kit	Five interchangeable nozzles in the box, for different patterns and tasks.
Materials	High-density polyethylene tank with polypropylene and nylon components in the chassis and fluid path.
Dimensions and weight	About 8 inches wide and 19 inches tall, item weight about 8.93 pounds empty.
Recommended uses	Garden and lawn spraying, weed control, fertilizers, and general chemical spraying.
Coverage per tank	Coverage depends on your calibrated output. Turf rates are often given per 1,000 square feet. As an example only, at one gallon per 1,000 square feet a full 4-gallon tank would cover about 4,000 square feet. Calibrate to your label.
Safety and PPE	Always follow the pesticide label. Wear the PPE specified on the label. If none is listed, extension guidance recommends at minimum chemical-resistant gloves, long sleeves and pants, closed shoes, and eye protection that meets ANSI Z87.1. Indoors with mechanically pressurized sprayers, a NIOSH-approved filtering facepiece or half-mask respirator may be required by some labels.
Warranty	Some listings advertise a 12-month warranty. Check the seller page for exact terms.
Country of origin	China.

 

How to Use and Installation Guide

Unbox, assemble, and power up

Set the tank on a stable surface, then fit the shoulder straps and chest strap to your body before you fill it. Attach the telescopic wand to the hose hand-tight, install your preferred nozzle, and check that the in-line strainer and nozzle screen are seated clean. Slide in the included battery or a compatible Makita 18 volt pack until it clicks, then turn the sprayer on and verify the pressure knob responds smoothly. Retail listings for this VAXMAY 4 gallon, 100 PSI, Makita 18V compatible sprayer show a telescopic wand, a five-nozzle set, and a bundle that often includes a 2.5 to 2.6 amp hour battery and charger, so you can test everything before mixing chemicals.

Pick the right nozzle and set an initial pressure

Start with a flat-fan tip for uniform broadcast herbicide passes, or a cone pattern for targeted work around ornamentals or for penetrating foliage. This is not marketing language, it is nozzle science. Extension and engineering guides explain that flat-fans are the dominant choice for uniform herbicide coverage, while cones are used for directed or spot applications. If drift is a concern, consider a low-drift flat-fan or a larger orifice that produces coarser droplets at the same flow. Increase pressure for finer droplets and coverage, decrease pressure for larger droplets and less drift, then recalibrate if you move the pressure knob significantly.

Mixing safely, with the right order

Always read the product label and Safety Data Sheet, gear up with label-required PPE, and mix outside or in a well-ventilated area. A common, label-aligned mixing sequence used by universities is remembered with WALES or its updated form A-W-A-M-L-E-S. In short, start with water and agitation, then add ammonium sulfate if required, next add wettable powders and water-dispersible granules, then flowables, then emulsifiable concentrates, and place surfactants or oils last. When in doubt, run a jar test first to check physical compatibility before you commit a full tank.

Labels specify glove material by solvent category, for example nitrile or butyl rubber, and refer to ANSI Z87.1 for protective eyewear. If your label is silent on eyewear, state agencies and OSHA resources point you to Z87.1-rated splash goggles or a face shield as a sensible baseline. Respirators are only used when the label or SDS requires them, and they must be NIOSH-approved for the hazard.

Calibrate your output once, then recheck after any change

The goal is simple, apply the labeled rate to the right area. The easiest path for backpacks is the one-one-twenty-eight method. Mark a 340 square foot plot, which is one one-hundred-twenty-eighth of an acre. Spray that plot at your normal walking speed and pressure, record the time, then spray into a measuring jug for the same time. The number of fluid ounces you catch equals your gallons per acre. If you collected 20 ounces, your sprayer is delivering 20 gallons per acre at that setup. Adjust pressure, tip size, or pace to reach your target, then note your settings. This method is used by Alabama Extension and UF IFAS because it keeps the math friendly and the results repeatable.

Prefer an area-based check. North Carolina State’s calibration sheet suggests spraying a measured area at a steady pace, timing yourself, then spraying into a container for the same time to read your flow. Penn State’s woodland guide gives a practical twist, measure your actual swath width, divide 340 by that width to find the calibration course length, and spray that lane to determine output. These approaches all agree on the rule, change pressure, nozzle, or walking pace, and you must recalibrate.

Dial in drift control before you start

Measure wind with a pocket anemometer, do not guess. University and EPA materials consistently recommend spraying in a gentle, steady breeze, often defined as roughly three to seven miles per hour, and to avoid conditions over about ten miles per hour or under about three when temperature inversions are likely. Keep the nozzle as close to the target as practical, select coarser droplets when near sensitive plants, and avoid spraying when wind blows toward them. If the wind direction shifts during the job, stop or expand your buffer.

Cleaning and decontamination that protects your plants

As soon as you finish, spray out the remaining mix on the labeled site, then triple-rinse. Drain the tank, flush with clean water through the hose and nozzle for roughly ten minutes, then refill with water and a cleaner and recirculate for about fifteen minutes, spray some through the nozzle, and drain again. Remove strainers and tips and clean them separately. For some herbicides, especially those that injure broadleaf ornamentals at very low concentrations, a detergent or ammonia-based cleaner is recommended in the second rinse. State extension clean-out tables give herbicide specific recipes. Dispose of rinsate only where the label allows.

Storage and maintenance

Store the sprayer dry, strainers and tips removed, straps unbuckled, and the battery off the unit. Periodically inspect the hose, O-rings, and nozzle screens, and replace worn parts before they fail under pressure. If you see pulsation or low output, check the inlet strainer first, then the nozzle screen, and confirm you did not dial the pressure down during a refill. These are the most common real-world causes of weak spray on battery backpack units, as seen in shop troubleshooting guides and owner reports.

VAXMAY’s listing highlights Makita 18 volt compatibility, which is handy if you already own LXT packs. Rotate freshly charged batteries through longer jobs, and avoid deep discharges to extend pack life. Some storefronts also bundle a stand-alone 2.5 to 2.6 amp hour pack and a charger so you can get started, then add your own higher capacity packs for longer runtime. Always verify the exact bundle on the specific seller page before purchase.

Frequently Asked Questions

Is the VAXMAY 4 gallon battery powered backpack sprayer really compatible with Makita 18 volt batteries, and what comes in the box?

Yes, current retail listings describe the VAXMAY as compatible with Makita 18 volt packs. Many listings also show a bundle that includes a 2.5 to 2.6 amp hour battery and a charger so you can spray right away, then rotate in your own Makita LXT batteries later if you have them. Always confirm the exact bundle on the seller page before you purchase, since third-party listings can vary.

I see some listings say 100 PSI and others say 75 PSI. Which one is correct?

This brand appears as a private-label model on several storefronts, and the maximum pressure shown does vary by listing. For example, one Amazon product page calls out 100 pounds per square inch, while a Newegg listing for the same four gallon VAXMAY shows 75 pounds per square inch. If hitting a specific top-end pressure matters for your nozzle choice or reach, double-check the exact spec on the page you plan to buy from.

How much area can I cover with one full 4 gallon tank on this Makita 18V compatible sprayer?

Coverage depends on your calibration, nozzle, and walking pace. A simple method used by Alabama Extension is the one-one-twenty-eight check. Time how long it takes you to spray 340 square feet at your normal pace, then spray into a measuring jug for the same time. The ounces you collect equals your gallons per acre. That number tells you exactly how many gallons you need per thousand square feet on your lawn. Many lawncare users aim for one gallon per one thousand square feet as a working target, but you should calibrate to your labels.

Which nozzle should I use for herbicides, insecticides, and foliar feeding?

University guidance is consistent. Flat-fan tips are the go-to for uniform broadcast herbicide work on turf and bare ground. Cone patterns are useful when you need penetration into foliage or a tighter, directed pattern for spot treatments around ornamentals. Purdue’s and Georgia’s guides also explain that dual or multi-fan tips split the pattern and can help with coverage in some cases. Pair your nozzle with the pressure you need for the droplet size the label recommends.

What is the best way to calibrate this 100 PSI garden sprayer so I hit the label rate?

Use a recognized method and write your settings down. The one-one-twenty-eight method from Alabama Extension is fast and repeatable in a yard setting. Penn State’s recordkeeping guide adds easy logs and an alternative one-thousand-square-foot approach that also works well for home lawns. Whichever you choose, keep pressure constant and walk the same pace you used during calibration.

How do I keep spray from drifting onto my tomatoes or the neighbor’s roses?

Check the wind with an anemometer, do not guess. EPA drift pages and several university sources recommend working in a light, steady breeze, often in the 3 to 10 miles per hour range, and avoiding dead calm that can indicate a temperature inversion. Keep the nozzle as close to the target as practical, use coarser droplets when near sensitive plants, and stop if wind direction shifts toward them. The telescopic wand on this five-nozzle backpack sprayer helps you place the pattern precisely along edges and foundations.

Can I run bleach or disinfectant through this backpack sprayer?

It is safer to dedicate a separate, bleach-rated sprayer if you intend to use sodium hypochlorite. UC ANR cautions against using flammables, acids, or caustics such as bleach in a standard pesticide backpack, since these can damage components and create hazards. Solo notes that bleach can corrode seals over time, and Chapin sells sprayers with special seals that tolerate bleach better, which underscores the point about dedicated equipment. Never mix bleach with ammonia. That combination releases dangerous chlorine gas.

Can I use one sprayer for herbicides and also for insecticides or fertilizers?

It is possible, but many pros avoid it because herbicide residues can injure ornamentals even at very low levels. If you must share, clean thoroughly using extension-recommended procedures, including triple rinsing and the correct cleaning agent for the product you sprayed. Many professionals keep separate tanks, for example one for non-selective herbicide, one for selective turf herbicide, and one for fertilizers or biologicals, to reduce the risk of cross-contamination.

What personal protective equipment should I wear while using this Makita 18V compatible sprayer?

Follow the product label first. If the label is silent, state resources recommend at minimum chemical-resistant gloves, long sleeves and pants, closed shoes, and eye protection that meets ANSI Z87.1. Oregon OSHA is explicit that wraparound safety glasses are not adequate protection when spraying. Respirators are worn only when required by the label or Safety Data Sheet, and must be NIOSH approved.

How do I clean the sprayer after a tough lawn herbicide so I do not scorch my shrubs next week?

Nebraska Extension’s clean-out guide calls for draining the tank, flushing lines and nozzles, running a detergent or tank cleaner through the system, then repeating with clean water, while physically removing and cleaning strainers and tips. Ag PhD’s tank cleanout table gives product specific recipes and reminders, including the critical caution to never combine bleach with ammonia. Dispose of rinsate only where labels allow.

How long will a battery last on a cordless backpack sprayer like this?

Runtime depends on pressure, nozzle size, and how much stop-start you do. Makita’s own 18 volt LXT four gallon sprayer is rated to spray up to 165 gallons on a single 4.0 amp hour battery, which gives you a realistic benchmark for an efficient 18 volt platform. VAXMAY listings often include a 2.5 to 2.6 amp hour pack and charger in the box, so plan your expectations accordingly and consider rotating higher capacity LXT batteries for long jobs.

Is it safe to use Makita LXT batteries on third-party tools that claim compatibility, like this sprayer?

Many users do it, but there is an element of risk. Community discussions point out that Makita batteries have built-in protection, and compatibility depends on how the third-party tool handles low-voltage cut-off and communication pins. If you choose to use your LXT packs, monitor temperature, avoid deep discharges, and stop if the pack or tool behaves oddly. This is not Makita’s own sprayer, so use common sense and check your warranty terms.

What mixing order should I follow when I tank mix herbicides, surfactants, and fertilizers in this five-nozzle backpack sprayer?

Labels rule, always. If the label does not specify, several universities teach the WALES or the updated A-W-A-M-L-E-S sequence as a safe default: start with water and agitation, add ammonium sulfate if required, then dry formulations such as wettable powders and water dispersible granules, then flowables and suspensions, then emulsifiable concentrates, and add surfactants last. If you are unsure, do a quick jar test before committing a full four gallon tank.

Does VAXMAY’s telescopic wand actually help with perimeter pest control or is it a gimmick?

A telescoping wand is a real advantage for crack-and-crevice and foundation work because it lets you keep the nozzle very close to the target without stepping into beds or reaching awkwardly. Combine a cone nozzle with lower pressure to create larger droplets, then trace the base of walls and entry points. That approach aligns with nozzle pattern guidance and drift reduction practices from extension sources.

Any quick way to decide if today is a safe spraying day before I gear up?

Check the wind and watch for inversion clues. If wind is less than about 3 miles per hour, be cautious because a temperature inversion may be present. Avoid spraying in calm conditions and avoid high winds that exceed label limits. Work in a light, steady breeze that carries spray away from sensitive plants. Simple cues and an inexpensive anemometer will save you frustration and plant damage.

Conclusion

If you are ready to stop guessing at coverage and start applying with confidence, this battery powered backpack sprayer 4 gallon setup gives you the two things that matter most in the field, steady pressure and smart control. Consistent pressure makes calibration stick, which is why university guides teach simple methods like the 1/128 calibration check to lock in an accurate flow, then keep your walking pace and settings the same across the job. Pair that consistency with the right tip, for example a flat-fan for uniform herbicide passes or a cone pattern for targeted work, and you get results that look professional without fighting a hand pump.

Good technique protects your lawn and your neighbor’s roses. Before you pull on the straps, read the wind and avoid dead calm that hints at a temperature inversion, then aim for a light, steady breeze. When the breeze picks up, move to coarser droplets and keep the nozzle close to the target. These best practices are echoed by national stewardship programs and federal guidance, and they make a visible difference in drift control with any 100 PSI garden sprayer.

This model’s Makita-compatible design is a practical win if you already run LXT tools. For a sense of what an efficient 18 volt backpack system can do, Makita’s own 4 gallon unit publishes up to 165 gallons per charge on a 4.0 amp hour pack. Treat that as a benchmark to plan your runtime and rotations, then verify the exact pressure and bundle details on the product page you are buying. That way your Makita 18V compatible sprayer and telescopic wand weed sprayer routine stays predictable from the first tank to the last.