Chapin 63924 4-Gallon 24V Battery Backpack Sprayer With Adjustable Brass Nozzle

Description

If you are done wrestling with hand pumps and short hoses, the Chapin 63924 4-Gallon 24V Battery Backpack Sprayer With Adjustable Brass Nozzle steps in like a quiet, steady helper that just keeps going. Its 24V lithium-ion system delivers up to about two hours of continuous spraying per charge, which Chapin rates at roughly 58 gallons, so you can walk your property with even pressure and a clear tank you can actually see into.

Key Customer Benefits

• Finish big jobs in one charge, without the stop-start fatigue. The 24V lithium-ion system on the Chapin 63924 keeps steady pressure and delivers up to about two hours of continuous spraying per charge, which Chapin translates to roughly 58 gallons. That means fewer refills and a more even application across lawns, beds, fence lines, and outbuildings.
• Cleaner, more consistent spray with fewer clogs. A three-stage filtration path protects the pump and nozzle, starting with the wide 6-inch filter basket at the tank opening, then an in-tank filter, then a final screen at the shut-off. In the field that simply means your fan pattern stays uniform and you spend less time fiddling with tips.
• Real control from the adjustable brass nozzle and included tips. Twist the brass cone for a tight stream or open it up for a fine mist for foliar feeding or insect control, and swap to the poly fan or poly adjustable tips when you want a sheet pattern along edging or driveways. That flexibility lets one battery-powered backpack sprayer handle weed control, fungicides, and perimeter pest jobs.
• Comfort you actually feel at the end of the day. The translucent 4-gallon poly tank sits on padded backpack straps, and the cushioned grip shut-off reduces hand fatigue during longer runs. If you have multiple zones to cover, those details add up to better posture and fewer sore shoulders.
• Reach and coverage for real-world properties. Retailer testing lists a typical horizontal stream in the mid-20-foot range and notes practical operating pressures suitable for turf and ornamental work. That extra reach helps when you are treating fence lines, ditches, or the back side of hedges without stepping into thorny beds.
• Built to be serviced, not tossed. Chapin publishes a detailed parts list and makes common wear items easy to replace, including the 6-8122 brass nozzle, filters, wand, hose, and even the battery and charger. When a sprayer is part of your weekly routine, that parts support protects your investment and keeps you spraying.

Product Description

What it is

The Chapin International 63924 4-gallon 24V Extended Spray Battery Backpack Sprayer is a pro-grade, lithium-ion powered sprayer built for lawn care, gardens, and perimeter pest control. It pairs a translucent 4-gallon poly tank with a 24-volt rechargeable battery that keeps pressure steady for up to about two hours of continuous use, which Chapin equates to roughly 58 gallons on a single charge. The kit includes three interchangeable nozzles, an adjustable brass cone, an adjustable poly cone, and a poly fan, so you can shift from a fine foliar mist to a targeted stream without changing tools.

How it works

Press the trigger and the internal pump comes to life, maintaining operating pressure while you spray. The battery recharges in about three and a half to four hours, so you can top it off at lunch and be ready for an afternoon route. A wide six-inch opening with a filter basket makes filling and rinsing straightforward, while Chapin’s three-stage filtration system screens debris at the tank mouth, inside the tank, and at the shut-off, which helps keep your pattern consistent and reduces clogging during long days. The cushioned shut-off, 20-inch wand, and padded backpack straps turn what used to be a tiring pump-and-pray chore into a controlled, even application.

What makes it effective and different

Two things separate this model in real use. First, the endurance and consistency. The 24V pack eliminates the pressure swings you get with manual pumps, which means your herbicide or insecticide goes down at a steadier rate over the whole property. Chapin publishes 40 to 60 PSI operating pressure with a flow of about 0.4 to 0.5 gallons per minute, which is right in the sweet spot for turf and ornamental work. Second, the control.

With the included tips you can walk a clean fan along edging, then twist the brass cone for a tight stream to reach the back side of shrubs. Independent retailer testing lists a practical horizontal reach in the mid-20-foot range, useful when you need to hit fence lines or ditches without wading into brush. The company also makes parts easy to find, from the 6-8122 brass nozzle to filters and hoses, which protects your investment over years of seasonal spraying.

Product Specifications

Spec	Detail
Model	Chapin 63924
Tank capacity	4 gallons, translucent poly tank
Battery & run time	24-volt lithium-ion; up to about 2 hours or roughly 58 gallons per charge; recharge in about 3.5 to 4 hours
Operating pressure	Manufacturer lists about 40 to 60 PSI; actual working range varies by tip and flow setting
Flow rate	About 0.4 to 0.5 gallons per minute
Hose & wand	48-inch reinforced hose; 20-inch poly extension wand
Nozzles included	Adjustable brass cone, adjustable poly cone, poly fan; quick twist to change pattern
Filtration	3-stage system: 6-inch filter basket at the mouth, removable in-tank filter, and a screen in the shut-off
Seals & compatibility	Chemical-resistant seals; widely used with labeled fertilizers, herbicides, fungicides, and insecticides
Spray reach	Horizontal reach commonly listed between about 22 feet and 30 feet depending on tip, pressure, and conditions
Dimensions & weight	About 14.75 in L x 9 in W x 22 in H; about 11.5 lb (empty)
Build & warranty	Made in the USA with global materials; 2-year limited warranty
Safety notes	Wear eye protection and gloves, never store chemicals in the tank, clean filters after each use; store battery on the charger in a cool, dry place

 

How to Use and Installation Guide

Before you start

Put safety first. Read the pesticide label and the Chapin International 63924 4-gallon 24V Extended Spray Battery Backpack Sprayer manual before mixing or spraying. Wear chemical-resistant gloves, long sleeves, long pants, closed-toe shoes, and eye protection. Keep bystanders and pets away. The manual calls out a pre-use check to confirm all hose, wand, and nozzle connections are tight and reminds you not to use corrosive cleaners like bleach in this sprayer.

Assembly and quick setup

Out of the box, attach the wand to the shut-off valve, making sure the small O-ring is seated, then tighten the retaining nut. Clip the lower ends of the padded straps to the metal frame and adjust for a snug, balanced fit. Drop in the three-stage filtration components. Stage 1 is the wide filter basket under the lid. Stage 2 is the removable in-tank filter next to the pump. Stage 3 is the small screen inside the shut-off handle. These filters are your first defense against clogs, so keep them in place.

Charge the 24V battery the right way

Slide the 24V lithium-ion pack into the charger before your first use. A solid red LED means charging, a solid green LED means ready. Chapin specifies about three and a half to four hours for a full charge, and it is acceptable to leave the pack on the charger once it turns green. The manual also recommends storing the battery on the charger when not in use, in a cool, dry place, away from direct sun or heat.

Prime the pump on day one

On first use or after long storage, fill the tank at least three quarters with clean water, turn the power switch on, secure the trigger open with a rubber band, and let the unit run until it develops a strong stream. Chapin notes this initial prime can take roughly 12 to 15 minutes. Once pressure builds, release the trigger and you are ready to mix product.

Calibrate for your lawn or beds

Calibration prevents over or under application. On pavement or a test area, mark out one thousand square feet, for example 50 by 20 feet. Spray that area with water using your normal walking speed and chosen nozzle. Time how long it takes. Then spray into a measuring container for the same number of seconds to learn how many fluid ounces you apply per one thousand square feet. Use that number to calculate total water and product for your actual area. Penn State Extension walks through both the one-thousand-square-feet method and the one-one-hundred-twenty-eighth-acre method, with clear math examples. Keep your wand height and pace the same during calibration and the real application.

For many labels that call for coarse droplets to reduce drift, use a fan tip and operate at the lower end of the pressure range recommended for that tip. Extension and stewardship resources repeatedly note that larger droplets drift less, while finer droplets give more coverage for foliar contact but are more likely to move off target. Always follow your product label if it specifies a droplet category like medium or coarse.

Mix and fill without the mess

Keep the filter basket in place. Add some clean water first, then add the labeled amount of product, then top up with water. Stir with a clean stick until fully mixed. The Chapin manual explains this sequence and reminds you that you do not need to fill the full four gallons if your job is smaller. Powders can be more abrasive. If you ever use a wettable powder, dissolve it thoroughly and clean the sprayer right away when you finish.

Choose and set the right nozzle

The 63924 ships with an adjustable brass cone, an adjustable poly cone, and a poly fan. Use the fan for uniform bands along edging, patios, and driveways. Use an adjustable cone for spot treatment or reaching into shrubs. If you later add TeeJet-style tips for specific patterns, many users report good compatibility with the Chapin wand, which makes it easy to match a labeled droplet category or flow rate. Keep in mind that higher pressure creates smaller droplets and a higher drift risk, while lower pressure produces larger droplets that resist drift.

Spray techniques that give pro-level results

Set the tank on your back and tighten straps so the weight rides high and close. Keep the wand slightly off to one side at about knee height. Walk at a steady, comfortable pace. Extension guidance says either a steady wand position or a gentle side-to-side pendulum can work, as long as you are consistent with what you used in calibration. Avoid windy periods. Keep your nozzle as close to the target as practical to reduce drift. Many crop and homeowner resources emphasize using the coarsest droplet size that still achieves coverage and keeping nozzle height low to the target. That same thinking helps around homes and landscapes.

Drift management note: Recent EPA labels commonly require medium or coarser droplets for certain actives. Even though you are doing ground applications, those label statements are mandatory. If your product’s label specifies a droplet class or sets wind thresholds, follow it exactly.

After spraying: cleanout that prevents cross-contamination

Empty any remaining solution by spraying it on the labeled target area. Then perform a triple rinse. Pacific Northwest stewardship guidance recommends: first drain, then flush the tank, hose, and nozzles with clean water for several minutes. Second, fill with water, add a recommended detergent if the label allows, recirculate and spray a little through the nozzle, then drain. Third, repeat with clean water. Clean or replace the shut-off and in-tank filters as needed. Do not use strong abrasives. The manual details where the two serviceable filters live and how to remove them for a warm, soapy soak.

Container tip: Triple-rinse empty pesticide containers and pour the rinsate into your sprayer tank so it gets applied to the labeled site. This is a best practice endorsed by national stewardship programs.

Storage and winterization

When you finish, turn the switch off, remove the battery, and store the sprayer clean and dry out of direct sun. Before freezing weather, drain the tank, hose, wand, shut-off, and nozzle to prevent damage. Chapin recommends storing the battery on the charger between uses. If your unit sits a long time, follow the priming procedure again before next season.

Problems and Solutions

If the pump runs but no spray comes out, prime the pump by spraying back into the tank until the pump cycles off, then resume. If you see a damp spot at the tank outlet, inspect the hose clamp and snug it. That clamp occasionally ships loose, and several owners report that replacing it with a slightly smaller clamp stops a persistent drip. Chapin’s troubleshooting table also points you to worn O-rings and loose nozzle or wand connections as common culprits.

Frequently Asked Questions

How long does the battery actually last and how long does a full recharge take?

Chapin rates the 24-volt lithium-ion pack for up to about two hours of continuous spraying, which they translate to roughly 58 gallons per charge. A full recharge typically takes about three and a half to four hours.
Pro tip: The manual says you can leave the pack on the charger once the light turns green. That helps keep it topped up between jobs.

Can I adjust the spray pressure on the Chapin 63924?

No. This model is designed to deliver a consistent output in the mid-30s to about 40 PSI. You control pattern and flow by changing or adjusting the nozzle rather than dialing the pressure.

My unit runs but will not spray. What should I try first?

Prime it. Chapin’s manual recommends filling the tank three quarters with water, switching the pump on, securing the trigger open, and letting it run until a strong stream forms, often around the 12 to 15 minute mark after long storage. On the troubleshooting page they also list common culprits like a loose hose clamp or air in the line. Several forum users echo that letting the pump dry out makes priming sluggish, so keep a little clean water in the system between uses.

Is it safe to leave the battery on the charger overnight?

Yes. Chapin’s charging notes state the charger and battery pack can remain connected with the green LED on. Store the charger and battery in a cool, dry place, and avoid charging outside the recommended temperature range.

What kind of spray distance should I expect?

It depends on your tip, angle, and wind. Retailers list typical horizontal stream ranges from about 20 to 30 feet for this model. Chapin and distributors also remind users that reach varies with nozzle orifice, tank pressure, wind, and the angle you hold the wand.
Pro tip: For trees or tall hedges, a narrow cone pattern on the brass tip will reach farther than a fan sheet.

Which nozzles come in the box and can I buy replacements?

You get three: an adjustable brass cone, an adjustable poly cone, and a poly fan. Chapin sells replacement and accessory tips, including the 6-8122 brass adjustable cone nozzle. The manual also lists complete nozzle kits and filter kits if you ever want to refresh the whole spray end.

Can I put a longer wand on the 63924?

Yes. Chapin’s 40-inch chrome or stainless wand, part 6-7772, is listed by Chapin for most backpack sprayers and retailer Q&A confirms fit for the 63924. A longer wand helps when you want more reach without raising nozzle height too much.

Can I run bleach or strong cleaners through this sprayer?

Avoid harsh or corrosive cleaners. The manual’s cleaning section advises against strong cleaning agents or abrasives. If you are using general household cleaning solutions, follow your cleaner’s label and the sprayer manual, then rinse thoroughly. Never leave chemicals in the tank after use.

Can I use wettable powders?

Yes, with extra care. Chapin notes that powders can be abrasive. Dissolve them thoroughly and clean the sprayer right after the job to reduce wear on nozzles and seals.

What is the warranty on the Chapin 63924?

Chapin lists a two-year limited warranty for this model on their product page, and they encourage owners to register online. Some retailer answers mention one year for certain parts, so check your packaging and the official warranty page for coverage details.

Can I use another brand’s 24-volt battery?

Do not. The manual warns that this sprayer is designed to operate with a Chapin 24-volt lithium-ion battery only. Using other batteries can cause damage or injury. Replacement battery kit part number is 6-8238.

What are the exact dimensions and weight?

Chapin publishes 14.75 inches long by 9 inches wide by 22 inches high, and about 11.5 pounds empty. That lines up with distributor listings.

I found a small drip at the tank outlet. Is that common?

It can happen if the hose clamp or retaining nut loosens. Chapin’s troubleshooting table calls out a loose hose clamp at the tank outlet as a cause of leaks. Snug the clamp and check the O-rings. Replace worn gaskets as needed.

Conclusion

If you are ready to stop pumping and start applying with calm, even pressure, the Chapin 63924 battery backpack sprayer is an easy win. The 24-volt lithium-ion system keeps output consistent for up to about two hours, which Chapin equates to roughly 58 gallons on a single charge. That endurance means steadier application rates, cleaner edges, and fewer refills when you are tackling weed control, foliar feeding, or perimeter pest jobs. The three included tips, including the adjustable brass nozzle, give you real control from a fine mist to a tight stream, while the wide-mouth, translucent 4-gallon tank and three-stage filtration keep clogs at bay and cleanout simple.

What I like most is that the numbers line up with field reality. Independent retailer listings and pro Q&A confirm the unit delivers a steady mid-30s to about 40 PSI with practical reach into the mid-20-foot range, which is right where most turf and ornamental labels want you to be for droplet size and drift control. When the day is done, a full recharge typically takes about three and a half to four hours, and Chapin’s manual notes you can leave the pack on the charger once the light turns green. In other words, it is ready when you are.