Dewalt DCST990M1 40V MAX XR 4.0 Ah Lithium-Ion Brushless 15 in. String Trimmer

Model: dewndcst990m1
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Dewalt DCST990M1 40V MAX XR 4.0 Ah Lithium-Ion Brushless 15 in. String Trimmer Model: dewndcst990m1

Product Features & specs :

Dewalt DCST990M1 40V MAX XR 4.0 Ah Lithium-Ion Brushless 15 in. String Trimmer

The 40V MAX String Trimmer features a patented gear drive design for amplified torque when powering through overgrowth. The bump feed head provides 15 in. of swath with DEWALT's 0.080 in. line (0.095 in. line is also compatible). The variable speed trigger offers precise power control as well as performance and runtime management with the Hi/Lo speed control switch.
  • 15 in. Cutting swath with 0.080 in. line (also accepts 0.095 in. line)
  • Patented gear drive design that powers through overgrowth
  • High-efficiency brushless motor maximizing run time and motor life
  • Variable trigger with hi/lo speed control for added power or extended runtime
  • Part of the 40V MAX system of Outdoor Power Equipment
What’s Included:
  • 40V MAX XR 4.0 Ah Lithium-Ion Brushless 15 in. String Trimmer - DCST990
  • 40V MAX 4.0 Ah Lithium-Ion Battery - DCB404
  • 40V MAX Lithium-Ion Battery Charger - DCB114
  • 0.080 in. Pre-wound Line in Spool
Power Source
UL Safety
CSA Safety
Wifi compatibility
Batteries Included
Battery Type
Starter Type
Case Included
Speed Settings
Bluetooth Compatibility
Battery Amp Hour
4 Ah
Motor Type
Blade Construction
Charge Time
1 Hour 30 Minutes
Charger Included
ETL Safety
Battery System
13 lbs.
Warranty Term
3 Year

Reviews :

4.6 / 5.0
27 Reviews
5 Stars
4 Stars
3 Stars
2 Stars
1 Star
Would you recommend this product?
Yes (11)
No (2)
Powerful (11)
Lightweight (6)
Heavy (1)
Best Uses
Frequent Use (1)
Love it!!
Better than my gas trimmer.....that won’t start at all.
August 19, 2018
Originally posted at
needed string trimmer, no oil or gas, after reading all reviews of DeWalt cordless trimmers the choice was easy. The 40 volt. I was hoping it would be the 20 volt or 60 volt as I have many tools using those batteries , but ease of use and power all pointed to the 40 volt and I am very happy with it. Having got the 40 volt trimmer it will now be easier for me to get other 40 volt DeWalt yard tools.
June 14, 2018
Best I Have Ever Had!
Works great! Battery lasts far longer than I was expecting.So much easier than gasoline. Just put the battery in and pull the trigger.
May 17, 2018
Originally posted at
I have been an avid gardener and this is the best trimmer I have ever used. It is so easy to use and I like the power generated on a battery operated trimmer.
April 17, 2018
Originally posted at
Best buy I have made in a long time
This machine has more power than any gas weed eater I have bought in the past. cutting mostly weeds and not grass. Use safety glasses as noted. Great to have a battery powered tool that negates all the problems with gas tools.
June 23, 2017
Very nice tool
I like how it cuts the weeds quickly. The battery only lasts about 30 minutes for me, but my body wants to quit before then, so it is fine. I just work until the battery drains and then go recharge it and take a break.
April 14, 2017
Would you recommend this product?
Could not even get the battery to charge!!!!
I could not even get this product to charge.. Like the manual says the light will blink when charging 12 Hours and still blinking I will see if I still get the blinking light tomorrow if so it goes back to Lowes!! I guess there is no quality control at DEWALT anymore!!
August 27, 2016
Would you recommend this product?
Headline is very descriptive and concise
Powerful trimmer with plenty of battery life for my uses. The double string forces bumping when one string breaks before the other and that causes a little line loss each time.
August 3, 2016
Would you recommend this product?
Outstanding poroduct.
Use it for weeding, it has plenty of power.
August 1, 2016
Would you recommend this product?
It works good, powerful, but HEAVY!
Had trouble with self feeding but finally got it working good
August 1, 2016

Q & A :

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Browse 10 questions Browse 10 questions and 10 answers
Will the 20 volt work with the 40 volt
todd on Aug 2, 2016
BEST ANSWER: No, the two systems are not cross compatible
how do you put new line on spool?????????????????
we have tried for over a half hour.
please help.
Michael on Jul 9, 2016
BEST ANSWER: Please contact Dewalt direct for technical support. You can reach them at 800-433-9258
Where can I get a replacement spool of string
Oly on May 7, 2016
BEST ANSWER: Cpo does carry replacement spool of sting or this item.
Dewalt DWO1DT802 0.080 in. x 225 ft. String Trimmer Line $13.99
Dewalt DWO1DT801 0.080 in. x 50 ft. String Trimmer Line $6.99
Is the recon 40 volt dewalt string trimmer included in the free battery rebate program
Flapp on Apr 27, 2016
BEST ANSWER: No,Dewalt is not running a free battery promotion for the string trimmer.
how long of time in one continual use do the battery last ?
Unlucky on Dec 11, 2015
BEST ANSWER: The battery run time will range from 15-30 minutes based on usage
I noticed an extended flat plate at the base of the battery housing. is there a wall hanging accessory for this plate to hang on? If so, where do I get one?
Fernando, retired on Jul 7, 2015
BEST ANSWER: This trimmer does not come with a wall mounting bracket nor is there a dedicated bracket.Might want to try the Gladiator wall mounting kit.
What is the expected life time of the battery for normal home usage?
RB on Jun 14, 2015
BEST ANSWER: The battery lasts about an hour.
Does DeWalt make an edger
PONCHO on Jun 5, 2015
BEST ANSWER: They make a trimmer but not an edger at this time.
How long does it take to recharge the battery? Also how long do these 40V batteries last?
Yard Diva on May 10, 2015
BEST ANSWER: This kit comes with a 45 minute charger. Theoretically, the battery will last 45-55 minutes. Practically, it depends on how hard you push the unit.
How long is the battery life before next recharge?
Tony on Apr 23, 2015
BEST ANSWER: That really depends on the usage. In our estimates that battery cycle can range from 25 - 50+ minutes depending on how its used.