Model#: DEWNDCST990H1

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Dewalt DCST990H1 40V MAX 6.0 Ah Li-Ion XR Brushless 15 in. String Trimmer

  • Dewalt DCST990H1 40V MAX 6.0 Ah Li-Ion XR Brushless 15 in. String Trimmer
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Frequently Bought Together


The Dewalt DCST990H1 40V MAX 6.0 Ah Cordless Lithium-Ion XR Brushless 15 in. String Trimmer features a variable speed trigger to give you precise speed control when needed with power and performance to tackle thick growth. The dual-line bump feed head clears a full 15 in., and the patented gear drive design amplifies torque enclosed in a metal gear case for high durability.
  • Brushless motor for a longer life
  • Dual 0.080 in. line with bump feed cuts through thick matter
  • Variable trigger with speed control provides precise speed control
  • Metal gear case for on the job durability
  • Patented gear drive design amplifies torque
  • 40V MAX Cordless Lithium-Ion XR Brushless 15 in. String Trimmer - DCST990
  • 40V MAX 6.0 Ah Lithium-Ion Battery - DCB406
  • 40V MAX Lithium-Ion Battery Charger - DCB114
  • Auxiliary Handle and Guard
  • 0.080 in. Pre-wound Line in Spool
Compliance and Restrictions
warning: --


Cordless: Yes
Weight: 22.57 lbs.
Amp Hour: 6 Ah
Batteries Included: 1
Battery System: 40V MAX
Battery Type: Li-Ion
Blade Construction: String
Bluetooth Compatibility: No
CSA Safety: No
Case Included: No
Charge Time: 2 Hours
Charger Included: Yes
ETL Safety: No
Motor Type: Brushless
Powered Tool Power Source: Electric - Cordless
Speed Settings: 2
Starter Type: Electric
UL Safety: No
Voltage: 40V
Wifi compatibility: No



4.6 / 5.0
25 Reviews
5 Stars
4 Stars
3 Stars
2 Stars
1 Star
Yes, I would recommend this to a friend (11)
Powerful (11)
Lightweight (7)
Easy To Use (2)
Ergonomic Design (2)
Heavy (2)
Best Uses
Frequent Use (2)
Large Projects (2)
Small Projects (2)
Heavy Duty Requirements (1)
Perfect for me
I am a retired dad/carpenter and just recently got this as a gift for Father’s Day. With my time with it so far I absolutely love it and I’m skeptical with tools when I first get them. It’s so much lighter than gas powered, much less maintenance, and much less sound; all this with out no compromise. This is all great for my age and I presume for all ages as my nephews use it with easy. I’d recommend this for those who want a nice finish to their prestigious lawn with little effort! Amazes me and my curb side appeal!
This review was collected as part of a promotion
June 27, 2019
Originally posted at
I have had my XR string trimmer for @4 years. Strong, plenty of power. Very good battery life. I HAVE SPENT MORE TIME WINDING AND REWINDING THE CORD THAN ACTUALLY TRIMMING MY YARD. WHEN WILL THE ENGINEERS FIX THIS? I have bought multiple dewalt heads, use dewalt trimmer line, wound it loose, wound it tight, wound it medium
May 16, 2019
Originally posted at
Solid, powerful and well balanced.
I've used this tool one time thus far to trim the details on my property...56 trees and along 1,300 linear feet of walls, fence and concrete edges...all on a single charge of a 4.0 ah battery from my Dewalt hedge trimmer.

I had no use for the "high" setting...the low is super powerful and up to most challenges and, I found the machine to be well balanced, quiet and easy to use. Be sure to use air to blow the debris from the motor air intake so it stays cool. Due to the large area I take care of, I cleaned it halfway through the work and then after.

I highly reccomend this tool and the entire Dewalt battery tool line to every homeowner.
April 15, 2019
Originally posted at
Love it!
Got this as a gift last summer. Used it like crazy. Its not hard on its batteries, can work for a long time on a single battery. Love it so much intrimmed part of the empty lot next to my house! Recommand it. Great toy for grown ups on serious business. All the boys on the street are jealous. As powerful as gas, as ecofriendly as a tesla!
This review was collected as part of a promotion
November 19, 2018
Originally posted at
I've had it for about a year now and it still works like its brand new! I don't have much to trim so gas powered equipment just wasn't realistic. And the batteries seem to last forever before they need a charge!
This review was collected as part of a promotion
November 13, 2018
Originally posted at
the unit does my hole yard on one charge
the string area guard should be a bit bigger like smaller other brand string trimmers
July 1, 2018
Originally posted at
Nice for residential use.
I've had this trimmer for 2 years now and it has done everything that I need it to do. I don't know if it's commercial grade as they had claimed. The main frustration is the head of the unit. Other battery units sell pre-loaded cartridges, this one you have to wind yourself. Gas trimmers have blades and things that you can replace the string with, not this. I spend almost as much time messing with tangled string, etc as trimming the yard. Other than that I love this thing, I am a bit disappointed that they haven't come out with a different head by now though.
May 29, 2018
Originally posted at
great tool
Great tool to have. I own a 40V hedge trimmer, 40V blower and this one too. Bought it with the blower in the beginning of summer 2015. Was kinda on and off shoud i buy them or not but pulled the trigger and... never looked back since. I'm a landlord who taking care of his property's yards (seven so far on my own. Every week or two I will goo and cut the grass, trim bushes and weeds. I do it in 4 hours by myself and love my electric trio!!! I almost never use it on HI speed and it will cut the edges perfect, just put good quality string in it and you will be pleased with this tool. All three work great and add value to each other as a set a VERY VERY user friendly and maintenance free tools.
May 27, 2018
Originally posted at
I bought one of these either last year or the year before when they first came out. first let me say that the fuel system has not given me any problems, which is awesome. all jokes aside it is a very good residential string trimmer . I use it to cut a couple of yards per week and it does a very good job. the yards are 1/4 to 1/2 acre lots and I can get through them on one charge if everything is being maintained somewhat. I don't run it constantly wide open , common sense should tell you that there is a limited amount of power with a battery. over the years ,dealing with gasoline fuel problems , noise , and vibration I have welcomed this tool and it is certainly one of my favorite purchases.
May 8, 2018
Originally posted at
Can't run it on high for more than half an hour
I came here because I was wondering if this model had reviews for poor battery life. I'm glad to have found the review of a professional who says that it's because of the motor overheating. Either way, I bought this model because I have a 2 acre yard, and my old Ryobi doesn't have great battery life. I love the DeWalt trimmer, but all 3 times I've used it, I didn't even make it to the one hour mark. I assumed it was a battery issue, but it may be the overheating issue. I''ve been using it for both trimming and edging, so a lot of time on the high setting. Very disappointed. Will likely return.
April 15, 2018
Originally posted at

Questions & Answers

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Browse 12 questions Browse 12 questions and 21 answers
Is it any good at edging lawns?
Babs on Jun 23, 2016
BEST ANSWER: Absolutely! This trimmer is fabulous! I edge all my lawn along the my paver front walk, the concrete driveway, the road edge and all my planting beds.
This unit has all the power of a gas model but none of the hassle. Battery lasts a long time and recharges relatively quickly. I also have the hand held blower which is another great DeWalt product.
Can the battery in this trimmer be used in any of the De Walt chain saws or leaf blowers?
Paul on May 30, 2016
BEST ANSWER: This should work in any 40V Dewalt tool.
Will this trimmer also work with a dewalt 40V MAX 4.0 Ah battery?
kamysdad on Apr 26, 2016
BEST ANSWER: Yes this trimmer will take a 4AH battery. Expect to have less run time
Does the string rolled up or just cut to length and put in?
Bob on May 24, 2016
Sent from my iPhone
How long does battery last before needing charge
Israel on Sep 20, 2015
BEST ANSWER: Battery run times vary based on the usage. On average the run times will should range from 25-45 minutes
quin o on Jul 22, 2017
BEST ANSWER: ah means amp hours. The larger the number the longer that battery will last. Usually means larger (and heavier) battery. Go with the higher number for longer run time.
Is it made in USA?
jim on May 25, 2016
BEST ANSWER: No, it is made in China
Does the string rolled up or just cut to length and put in?
Bob on May 24, 2016
BEST ANSWER: This comes with a 0.080 in. Pre-wound Line in Spool
What are the shipping dimensions of this tool?
krpo on Apr 15, 2016
BEST ANSWER: The dimensions of the DeWalt DCST990H1 are 11.13 x 8.88 x 77.75 inches
I don't like the bump & feed heads. Will this take an aftermarket head where you just put in lengths of
strings? I never have luck with bump and feed.
Gary on Apr 9, 2016
BEST ANSWER: We can not confirm that Dewalt's trimmers can accommodate aftermarket accessories

New Vs. Reconditioned

What's the difference between New and Factory-Reconditioned?

Factory-Reconditioned products have been returned to the manufacturer and are restored to like-new operating condition; they go through a rigorous testing and inspection process. Plus, they offer a significant savings vs. new.
  • Reconditioned products may have minor cosmetic blemishes or scratches that do not affect item performance.
  • Reconditioned products may not come with all of the consumables the new version comes with (bits, sanding pads/papers, cases, etc.).
  • Both come with a manufacturer warranty and are covered by our Money Back Guarantee; New is 30 days, Reconditioned is 120 days.
Condition: New Factory Reconditioned
Features: Same Same
Specs: Same Same
Includes: 40V MAX Cordless Lithium-Ion XR Brushless 15 in. String Trimmer - DCST990,
40V MAX 6.0 Ah Lithium-Ion Battery - DCB406,
40V MAX Lithium-Ion Battery Charger - DCB114,
Auxiliary Handle and Guard,
0.080 in. Pre-wound Line in Spool
40V MAX Cordless Lithium-Ion XR Brushless 15 in. String Trimmer - DCST990R,
40V MAX 6.0 Ah Lithium-Ion Battery,
40V MAX Lithium-Ion Battery Charger,
Auxiliary Handle and Guard,
0.080 in. Pre-wound Line in Spool
Availability: Out of Stock Out of Stock
Warranty: 3 Year 1 Year