# Best Battery Backpack Sprayer



## Mozart (Jul 17, 2018)

Hey guys,

I have a Scott's hand pump sprayer but @wardconnor's latest video encouraged me to consider a battery backpack sprayer for consistency of application and ease of use.

What are the best options? Hopefully someone who has tried a few different brands can opine.

I want something that will have decent output and the ability to spray second floor windows with insect repellent (we have some spider issues).

Also important to me is the ability to use most of "the last drop" in the tank. I don't want lots of leftover product that I can't apply.

I would ideally also like a variety of nozzles and accessories for the future, for the unknowns. Rechargeable battery is also a plus.

I see options on Amazon for "my 4 sons" and chapin. Are these good brands? My budget is $200 but may need to be reduced if I don't get spousal sign-off :lol: so a cheap "plan B" recommendation would be appreciated as well.

On a related note: Are there any chemicals that need their own sprayer?


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## wardconnor (Mar 25, 2017)

Get the Chapin.

Lots of folks here have it and love it. Loads of info here. https://thelawnforum.com/viewtopic.php?f=4&t=170

You will get way better consistent pressure using it vs a hand pump like I was saying,

You will also want to read this thread as well about spray tips,

https://thelawnforum.com/viewtopic.php?f=4&t=33


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## Mozart (Jul 17, 2018)

Thanks :thumbup:

Does this come with a good fan tip sprayer or will I need to rig something like Grass Daddy did with his tee jet nozzles?


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## Mozart (Jul 17, 2018)

Got my Chapin and it is awesome.

I calibrated it today and I think my method is a lot easier than what I've seen online so I thought I'd share.

First I did a bucket test. I started the sprayer and timer at the same time. When the timer hit 15 seconds exactly I released the pump sprayer. This allows me to focus on an exact volume deployed in 15 seconds which is easier (IMO) than timing how long it takes to fill a quart (no need to stop the timer and sprayer at the same time - it's more like releasing the lever at the gas station to try and hit a round $ amount).

In 15 seconds I filled 360 mL. There are 3,785 mL in a gallon (and four 15 second intervals in a minute) so it takes (3,785/360)/4 = 2.628 minutes, or 2 minutes 37 seconds. Pretty close to @LawnCareNut's estimate of 2 minutes 38 seconds per gallon!

I'm not sure this step was needed for my calibration approach, but good to know there is consistency in output between sprayers of the same make/model.

To calibrate:

Step 1: Figure out an ideal height such that your fan tip is making an even application across the width of the ground (not too tall where the outer edges get significantly less than the middle). Probably knee higher or slightly below.

Step 2: Mark off 500 sqft on your driveway

Step 3: Fill sprayer with 5 L of water (more ticks for liters so better accuracy than gallons)

Step 4: Set your walk pace such that the application moving forward provides good coverage in a strip. For me this is a slow casual walk.

Step 5: walk in bands, back and forth across the 500 sqft and "kiss the tips" of the prior pass (as LCN would say). Don't need to time anything. Consistent pace across the area is most important - but you choose the pace that works for you.

Step 6: after you made a nice, even 500 sqft application, see where the water level is in the tank. For me it was slightly above 3L.

Step 7: Using the sprayer empty the tank into a measuring cup until you hit the next liter line. For me, I had to spray 50mL into a cup before the tank hit 3L.

This gives you a volume per sqft measure. I now know that at my preferred walking pace I spray 1.95L per 500 sqft.

When I need to determine how much to mix I would use that metric. So for 2500 sqft I would apply 9.75 liters of liquid (water + chemicals combined). The amount of chemical would be calculated based on the area treated.

This approach calibrates the sprayer to the user, not the other way around.

Are there any downsides to this approach? If chemicals need a specific dilution that may cause issues; but I'm not sure that the dilution matters much... does it?


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## Lawn_newbie (Jun 19, 2018)

Chapin as everyone else as stated, but get the 24V battery and not the 20V.


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## g-man (Jun 15, 2017)

@Lawn_newbie why?


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## Mozart (Jul 17, 2018)

The 24V lasts a little longer and can spray a little further, but the 20V model has a cooler logo.

Very unlikely I will need the extra battery (small yard). I think the 20V can spray vertically 23 ft? So I should be able to spray 30+ feet vertically given my 8 ft arm reach and 2 foot sprayer wand.

Really curious about my proposed calibration technique. Why does everyone calibrate their walk to the sprayer and not the other way around? Want to make sure I'm not missing something obvious.


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## XiolaOne (Jul 30, 2018)

Used my Chapin for the first time yesterday. Pretty slick


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## TommyTester (Jul 3, 2018)

Mozart said:


> Got my Chapin and it is awesome.
> 
> I calibrated it today and I think my method is a lot easier than what I've seen online so I thought I'd share.
> 
> ...


Your method is excellent imo, however based on discussions in the TeeJet thread, to get good uniformity, the lane's walking width needs to match the nozzle's height, assuming a flat fan-tip with a ~110 degree spread. Thus "Kissing the tips" for lane width is *clearly wrong* and results in severely under-applied streaks between lanes. Ideally, if your nozzle height is 20 inches, that should be your lane walking width too, so if you have a 21" mower, use the same lanes as you mow. That will use more gallons for your calibration area but it should result in nearly ideal uniformity, which is key.

Another way to look at it is, compare it to sprinkler head-to-head coverage. If a sprinkler's range is 20 feet, you don't place them 40 feet apart, you place them 20 feet apart to achieve good uniformity. Same goes for flat fan sprayers.


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## g-man (Jun 15, 2017)

The height depends on the nozzle angle.







I think I bought every single type. I've been using the AIXR11004 for all of my applications. Mainly for drift control. I also use the mower stripes to ensure the overlaps are correct.

Edit: I explained this the opposite way. Fixed it. I need my morning coffee.


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## N LA Hacker (Aug 17, 2018)

You can run 110 at 20 inches.


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## Mozart (Jul 17, 2018)

Interesting, thanks! So the fan tipped sprayer that comes with Chapin is 110 degrees? That seems about right.

I think I ended up spraying from approximately 20" height but maybe did not get enough overlap. I did err on the side of caution and when in doubt did a slight overlap versus leaving a gap.

How should the driveway look when finished calibrating? Should each lane be a continuous stripe of wetness (hard to find a dry spot assuming it doesn't evaporate)? Or should it look like a mist was sprayed on the pavement? I was going for stripes of wetness (without excess runoff) for my application of tenacity.


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## 7474 (Aug 20, 2018)

@g-man

Any reason not to use the Turbo Twin Jet with the Chapin? Rated as excellent across almost all of the spray categories.

Thanks.


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## 7474 (Aug 20, 2018)

Lawn_newbie said:


> Chapin as everyone else as stated, but get the 24V battery and not the 20V.


Love the battery power!! Spent the previous 10 years pumping a cheapo HF 4 gallon. Served me well but unbelievable how much nicer it is with a battery.

I got the 24v as a free upgrade from HD. Ordered the 20v with a price match and then it went on back order a week after it was supposed to be delivered to me. Got it for $101 out the door as HD previously price matched the 20v and they gave me the 24v to make up for the delay.

They later wound up sending me (4) 20v sprayers and only charged me for (1) 20v. The 20v was supposed to be cancelled at the time of upgrade but never was.

Returned all 4 to HD and not even a thank you.


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## g-man (Jun 15, 2017)

@7474 I tried it and did not like the dual pattern of stuff. I want to stop right before the concrete edge (iron stains). The aixr is to my a great compromise of drift control and drop size. In my Reno, I made a straight line of round up just using the aixr.


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