# The right extension cord for my lawnmower? **URL:** \ **Category:** Factual Questions\ **Created:** [July 7, 2016, 6:42pm UTC](https://boards.straightdope.com/t/the-right-extension-cord-for-my-lawnmower/759323 "2016-07-07T18:42:30Z")\ **Posts on this page:** 18\ **Page:** 1
**Author:** ![crazyjoe](https://avatars.discourse-cdn.com/v4/letter/c/f14d63/32.png) [@crazyjoe](https://boards.straightdope.com/u/crazyjoe)\ **Post date:** [July 7, 2016, 6:42pm UTC](https://boards.straightdope.com/t/the-right-extension-cord-for-my-lawnmower/759323/1 "2016-07-07T18:42:30Z")
I have a 13 amp electric lawnmower. My lot is 100 feet wide, so a typical 100’ extension cord is not long enough to allow me to finish the job. It seems like finding 125 to 150 feet of extension cord (of any size) is impossible, so I have been working with a 100 foot cord plugged into a 50 foot cord. Is this OK, as long as both cords are rated at 15 amps (ie 12 gauge wire)? Or should I just give up and go back to gas mowing (yuck!) ---
**Author:** ![Sigene](https://avatars.discourse-cdn.com/v4/letter/s/df788c/32.png) [@Sigene](https://boards.straightdope.com/u/Sigene)\ **Post date:** [July 7, 2016, 6:49pm UTC](https://boards.straightdope.com/t/the-right-extension-cord-for-my-lawnmower/759323/2 "2016-07-07T18:49:55Z")
does the 50 ft and 100ft cord option work for you? Does it cut the grass to your satisfaction? If so, I would keep doing that. ---
**Author:** ![TriPolar](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/tripolar/32/3008_2.png) [@TriPolar](https://boards.straightdope.com/u/TriPolar)\ **Post date:** [July 7, 2016, 7:06pm UTC](https://boards.straightdope.com/t/the-right-extension-cord-for-my-lawnmower/759323/3 "2016-07-07T19:06:20Z")
Feel the extension cord, see how hot it is. ---
**Author:** ![crazyjoe](https://avatars.discourse-cdn.com/v4/letter/c/f14d63/32.png) [@crazyjoe](https://boards.straightdope.com/u/crazyjoe)\ **Post date:** [July 7, 2016, 7:12pm UTC](https://boards.straightdope.com/t/the-right-extension-cord-for-my-lawnmower/759323/4 "2016-07-07T19:12:36Z")
> [@TriPolar](#): > > Feel the extension cord, see how hot it is. I am constantly holding the extension cord, as you have to manage its path behind you on the lawn so you don’t run over it on your next pass. It doesn’t get really hot, or even noticeably warm. ---
**Author:** ![OldGuy](https://avatars.discourse-cdn.com/v4/letter/o/3bc359/32.png) [@OldGuy](https://boards.straightdope.com/u/OldGuy)\ **Post date:** [July 7, 2016, 7:20pm UTC](https://boards.straightdope.com/t/the-right-extension-cord-for-my-lawnmower/759323/5 "2016-07-07T19:20:57Z")
The advice is never to do this. However, people do it all the time. you should probably be safer than the typical misuse (often outdoor Xmas lights) as I assume you’re with the lawnmower all the time. You should be using an outdoor extension cord. And of course it’s amp rating should be high enough. As you are “cheating” on the length, I’d suggest not going with 15 amp cords, but using 20 amp cords. ---
**Author:** ![Marvin\_the\_Martian](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/marvin_the_martian/32/2898_2.png) [@Marvin\_the\_Martian](https://boards.straightdope.com/u/Marvin_the_Martian)\ **Post date:** [July 7, 2016, 7:47pm UTC](https://boards.straightdope.com/t/the-right-extension-cord-for-my-lawnmower/759323/6 "2016-07-07T19:47:47Z")
300 feet (you need to include both hot and return) of 12 gauge copper wire has about 0.5 ohms of resistance. 13A across 0.5 ohms gives a 6.5V voltage drop, so as long as your voltage is in spec the mower should still see at least 110V. You should be fine (I am assuming outdoor cords). I have used an electric mower at our vacation house for years. Much cheaper than a gas mower, pretty much zero maintenance, and a lot lighter. I also think the net emissions are a lot less, since I am ultimately using fossil fuels burned in a power plant (presumably somewhat efficient and with some pollution control) rather than a stinky little gas engine. I also use two extension cords (pretty much two that I had lying around. I tie a knot where the two cords join so they don’t pull apart. ---
**Author:** ![Chefguy](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/chefguy/32/138_2.png) [@Chefguy](https://boards.straightdope.com/u/Chefguy)\ **Post date:** [July 7, 2016, 9:00pm UTC](https://boards.straightdope.com/t/the-right-extension-cord-for-my-lawnmower/759323/7 "2016-07-07T21:00:34Z")
> [@crazyjoe](#): > > I am constantly holding the extension cord, as you have to manage its path behind you on the lawn so you don’t run over it on your next pass. It doesn’t get really hot, or even noticeably warm. Then you’re fine. Extension cords are not a problem when used like that for a temporary power feed. ---
**Author:** ![Dag\_Otto](https://avatars.discourse-cdn.com/v4/letter/d/439d5e/32.png) [@Dag\_Otto](https://boards.straightdope.com/u/Dag_Otto)\ **Post date:** [July 8, 2016, 2:16am UTC](https://boards.straightdope.com/t/the-right-extension-cord-for-my-lawnmower/759323/8 "2016-07-08T02:16:55Z")
The 13 amp is likely a peak rating rather than continuous, which helps. ---
**Author:** ![watchwolf49](https://avatars.discourse-cdn.com/v4/letter/w/e9c0ed/32.png) [@watchwolf49](https://boards.straightdope.com/u/watchwolf49)\ **Post date:** [July 8, 2016, 2:24am UTC](https://boards.straightdope.com/t/the-right-extension-cord-for-my-lawnmower/759323/9 "2016-07-08T02:24:16Z")
I’d do this with 12 gauge extension cords. I’d just use the 50’ piece until it ran out, then use the 100’ piece until that ran … then I’d use the whole 150’ for the finish. The place to check for overheating is where the cords plug into each other and the wall outlet. ---
**Author:** ![Crafter\_Man](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/crafter_man/32/458_2.png) [@Crafter\_Man](https://boards.straightdope.com/u/Crafter_Man)\ **Post date:** [July 8, 2016, 2:28am UTC](https://boards.straightdope.com/t/the-right-extension-cord-for-my-lawnmower/759323/10 "2016-07-08T02:28:39Z")
> [@TriPolar](#): > > Feel the extension cord, see how hot it is. In addition, _feel the receptacle end_. Last weekend I use an extension cord with an electric grill. (Was grilling some zucchini outside.) Afterwards I noted the end of the extension cord (the molded receptacle end of the extension cord, where the grill plugs in to) was quite warm. The other parts of the extension cord were O.K. I figured it must be due to contact resistance, either at the plug/receptacle interface, or the crimp connections inside the receptacle that is molded to the extension cord. ---
**Author:** ![md2000](https://avatars.discourse-cdn.com/v4/letter/m/73ab20/32.png) [@md2000](https://boards.straightdope.com/u/md2000)\ **Post date:** [July 8, 2016, 6:17am UTC](https://boards.straightdope.com/t/the-right-extension-cord-for-my-lawnmower/759323/11 "2016-07-08T06:17:19Z")
Typical electrical fires happen in the contacts - especially with weak connections between the wire and the outlet hardware. If the plug was warm, maybe it was not making firm contact with the socket, maybe the contact was somewhat corroded. Fix the first by bending the plug prong a bit, the latter by pushing the plug in and out of the socket over and over a few dozen times to wear away any build-up. if the problem persists, look into more in-depth repairs. ---
**Author:** ![albino\_manatee](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/albino_manatee/32/2_2.png) [@albino\_manatee](https://boards.straightdope.com/u/albino_manatee)\ **Post date:** [July 8, 2016, 6:41pm UTC](https://boards.straightdope.com/t/the-right-extension-cord-for-my-lawnmower/759323/12 "2016-07-08T18:41:31Z")
crazyjoe … i been partner with an electric mower for the past 15+ years … utilizing one 20’ chord mated with a 50’ length. that 50’ chord, being the lighter-gauge, is plugged into the appliance … the heavier-gauge 20’ conduit goes direct to the house-main. however, you state your property is 100’ in width … let’s say the depth is also 100’. distance between the farthest corners is approximately 140’ _(center-point being 70’)_. if your house-main is located within close proximity to that center-point … 75’ would be adequate … and 100’ is more than enough. the mower i been using is a 15-year old black&decker with 18" swath (model lm175) … she’s capable in mowing down knee-high weeds. within that 15 years, i’ve had to repair it three times _(electrical issues)_ and have sharpened the blade only once. veritably, b&d designed these to break down by fitting them with cheap parts. as for battery-driven options, crazyjoe … i’d suggest to stay away from this avenue … eon’s 20" 56v model costs $450 at home-depot and they typically need a second batt-pack _($125)_ to “complete the job”. purportedly, the batt-packs last 3-4 years before going _“kaput”_. and, from what i hear, their 56v models really are not all that powerful. ---
**Author:** ![albino\_manatee](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/albino_manatee/32/2_2.png) [@albino\_manatee](https://boards.straightdope.com/u/albino_manatee)\ **Post date:** [July 8, 2016, 6:56pm UTC](https://boards.straightdope.com/t/the-right-extension-cord-for-my-lawnmower/759323/13 "2016-07-08T18:56:00Z")
> [@Crafter\_Man](#): > > Afterwards I noted the end of the extension cord was quite warm. Crafter\_Man … that was a **gfci** outlet, i assume? ---
**Author:** ![crazyjoe](https://avatars.discourse-cdn.com/v4/letter/c/f14d63/32.png) [@crazyjoe](https://boards.straightdope.com/u/crazyjoe)\ **Post date:** [July 8, 2016, 7:26pm UTC](https://boards.straightdope.com/t/the-right-extension-cord-for-my-lawnmower/759323/14 "2016-07-08T19:26:15Z")
> [@albino\_manatee](#): > > crazyjoe … i been partner with an electric mower for the past 15+ years … utilizing one 20’ chord mated with a 50’ length. that 50’ chord, being the lighter-gauge, is plugged into the appliance … the heavier-gauge 20’ conduit goes direct to the house-main. > > however, you state your property is 100’ in width … let’s say the depth is also 100’. distance between the farthest corners is approximately 140’ _(center-point being 70’)_. if your house-main is located within close proximity to that center-point … 75’ would be adequate … and 100’ is more than enough. > > the mower i been using is a 15-year old black&decker with 18" swath (model lm175) … she’s capable in mowing down knee-high weeds. within that 15 years, i’ve had to repair it three times _(electrical issues)_ and have sharpened the blade only once. veritably, b&d designed these to break down by fitting them with cheap parts. > > as for battery-driven options, crazyjoe … i’d suggest to stay away from this avenue … eon’s 20" 56v model costs $450 at home-depot and they typically need a second batt-pack _($125)_ to “complete the job”. purportedly, the batt-packs last 3-4 years before going _“kaput”_. and, from what i hear, their 56v models really are not all that powerful. My lot is 100 x 150, but I do it in 2 sections, front yard and back yard. In both sections, the outlet is located near the far edge of the property, I do not have one centrally located, unfortunately. I experimented with battery powered mowers before this, and was underwhelmed. They do not do a very good job. ---
**Author:** ![herman\_and\_bill](https://avatars.discourse-cdn.com/v4/letter/h/f1d935/32.png) [@herman\_and\_bill](https://boards.straightdope.com/u/herman_and_bill)\ **Post date:** [July 9, 2016, 5:20am UTC](https://boards.straightdope.com/t/the-right-extension-cord-for-my-lawnmower/759323/15 "2016-07-09T05:20:59Z")
Go to an electrical supply store. You can purchase your cord to the length you need and add your own heavy duty connections. ---
**Author:** ![PoppaSan](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/poppasan/32/189_2.png) [@PoppaSan](https://boards.straightdope.com/u/PoppaSan)\ **Post date:** [July 9, 2016, 9:30am UTC](https://boards.straightdope.com/t/the-right-extension-cord-for-my-lawnmower/759323/16 "2016-07-09T09:30:09Z")
> [@crazyjoe](#): > > I am constantly holding the extension cord, as you have to manage its path behind you on the lawn so you don’t run over it on your next pass. It doesn’t get really hot, or even noticeably warm. You really shouldn’t have a problem outside with the cords as your explained. Using cords, I’ve learned to mow towards and away from the outlet. Don’t have to move the cord as much. Start in the middle and mow 1/2 with the cord on the uncut side then flip it once to the mowed side to finish up. ---
**Author:** ![Crafter\_Man](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/crafter_man/32/458_2.png) [@Crafter\_Man](https://boards.straightdope.com/u/Crafter_Man)\ **Post date:** [July 9, 2016, 12:36pm UTC](https://boards.straightdope.com/t/the-right-extension-cord-for-my-lawnmower/759323/17 "2016-07-09T12:36:29Z")
> [@albino\_manatee](#): > > Crafter\_Man … that was a **gfci** outlet, i assume? Yes, though I am not sure how that would be relevant. ---
**Author:** ![Me\_Billy](https://avatars.discourse-cdn.com/v4/letter/m/e480ec/32.png) [@Me\_Billy](https://boards.straightdope.com/u/Me_Billy)\ **Post date:** [July 9, 2016, 2:15pm UTC](https://boards.straightdope.com/t/the-right-extension-cord-for-my-lawnmower/759323/18 "2016-07-09T14:15:35Z")
Use 100 ft. of 12 gauge cord. Or 50 foot of 10 gauge, then 50 ft. of 12 gauge. These can be found at home improvement stores and are called “contractor cords”. They cost a small fortune if they are good. BE SURE IT SAYS 12 ga. or 10 ga. ON THE CORD PACKAGE! A large around cord MEANS NOTHING in this world of cheats an misrepresentation! The numbering is backwards… 10 gauge is larger than 12 gauge. The problem is called “voltage drop”. You can see what various sizes of wire will do with a “voltage drop calculator”. Use 120 volts and single phase. Voltage drop calculator… [http://www.windsun.com/Hardware/Voltage\_Calc.htm](http://www.windsun.com/Hardware/Voltage_Calc.htm)