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Solar Lawn Mower!

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Let's go green!
I've had battery powered lawn mowers before and the biggest problem I've had with them is keeping them charged. You have to either plug them in or take the battery out and that sucks.
This is one solution to the problem. Install solar panels on the mower and just leave it parked in the sun to charge it.
Here's how I did it!
 
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Step 1: Tools and Materials Needed

Tools
  • Soldering iron
  • Wire stripper
  • Volt meter
  • Screw driver
  • Wrenches
Materials
  • Battery Powered Lawn Mower
  • 2 - 12 volt Photovoltaic Solar Panels
  • 4 - General purpose rectifier diodes
  • Double-stick tape
  • Nuts, Bolts & Washers
  • Solder

Step 2: Evaluate the Lawn Mower's current condition

I had a DR Neuton Mower, but this Toro came up on Freecycle (www.freecycle.org) . It was way more mondo than the DR, so I decided it would be the donor machine.
The first thing I did was check the batteries. They were toast so I had to build a new battery pack.
I got four replacement batteries at my local electronic supply for $18.00 each. To keep them as a cohesive pack, I applied double-stick tape between each battery...just like the original setup had.
myrrhmaid5 months ago
I have mower envy! Nice one!
michaelb210 months ago
The panels provide no appreciable power when the mower is in use, why attach them to the mower? Now the mower must be left out in the elements so that the panels have access to the sun.
Marsh (author)  michaelb210 months ago
So what? Leave it out. It's not like the sun is going to hurt it. Any kind of plug will eventually wear out. Been three years and still works fine.
kinggargantuan11 months ago
I have that same fisher space pen. :)
Would this mower work on the solar cell alone, or is a batery needed? I guess you can just park it in the sun and operate of the battery. Will the charging stop if the battery is fully charged?
lol... no way it would run off just the solar panels.. I think you have a major misunderstanding about how much power solar panels produce. Those panels could hardly power an MP3 player, never mind a lawn mower
Sassah122 vmod3211 months ago
Actually no, I have exactly the same panel and I can power my 12 volt dvd player on a sunny day. But you are right, there is no way you could power a mower!
Marsh (author)  Sassah12211 months ago
It takes a week to recharge the mower for it's next use.
Marsh (author)  vmod323 years ago
These panels keep the batteries charged and ready all of the time. They're not very powerful. They probably won't overcharge it.
vmod32 Marsh3 years ago
Exactly, they just slowly charge the batteries. Very slowly since there are a lot of batteries. If you have a small lawn that does not need cutting very often, they may provide enough juice to never have to plug in the mower. Or at least extend the time between needing to plug it in. But there is no way the panels could power the mower without the batteries. They probably provide 1/1,000 of the power the mower would need to run. But store up all that power over several days in the batteries and your running the mower.
patenaude3 years ago
I'd be worried that if you left it out for long periods (weeks->months), that the panels would eventually cook the batteries.
Marsh (author)  patenaude3 years ago
time will tell.
sbeazley Marsh2 years ago
Let us all know when/ if that happens. Would be good info.
9w2xyz3 years ago
nice. Did the same thing with my truck. Came back to see the panels stolen. At least they left me the diodes...... pfffftttttt....
wirecutter3 years ago
Nice device but you only need ONE diode on each cell ( it is a series connection you can redraw it with the two diodes connected next to each other) as with two in Circuit you lose about 1/2 a Volt and that in the UK's sun is important in giving you a charge in to the battery. ( Image = 2 diode ) Even better is to join the positive of one panel to the negative of the other battery get rid of the junction to the middle of the batteries and then you only need one diode in the circuit and you are charging at 24 volts ( Image = 1 diode ) ++++++++++++
2 diode.jpg1 diode.jpg
ayup. both will work fine. First will charge even if the sun blocks one of the panels (though only one pair of batteries will charge), and the second will avoid a drop of six tenths of a volt by removing one diode.
lbrewer423 years ago
Goats work well for lawnmowers :^)
Marsh (author)  lbrewer423 years ago
No they don't. People fall in love with them and start feeding them Barleycorn and molasses. From that point on, they stop eating grass.
static Marsh3 years ago
That's a people problem, not a goat problem. :)
blained Marsh3 years ago
Only because barleycorn and molasses-fed goats TASTE better.
kill-a-watt3 years ago
this wouldn't last a week in my backyard unless locked in the shed.
Marsh (author)  kill-a-watt3 years ago
Ever consider getting a dog?
yes, but not for the sole purpose of guarding my lawnmower vs. locking it up.
Marsh (author)  kill-a-watt3 years ago
Ask any cop. The general consensus is that people who have dogs don't have their stuff stolen from their back yards. Even if it's just a yappy little rat-dog. You could always mount the PV panels on the roof of your shed and set it up to plug in when you park the mower inside. The kit I used must have come with 20' of wire and I re-used the plugs in the project.
xenor Marsh3 years ago
Someone stole a bag of dog food from my backyard (even when guarded by yappy chihuahua)
thebriguy Marsh3 years ago
...or add a car alarm (haha:-)
luvit3 years ago
you mow dirt, like me. you are full of awesome. i also mow my trash.. you?
EmmettO luvit3 years ago
I was going to say, "Of course the solar panels are enough to mow your lawn! I don't see any grass!" Just kidding though. Lawns are evil. I try to kill mine as much as possible by putting in gravel play yards, gardens and a big pit that is supposed to be a workshop one day.
Marsh (author)  EmmettO3 years ago
They had a program in Phoenix a few years back where they paid you to tear out your lawn and replace it with gravel. Now grass grows through the gravel and you can't get on it with a lawnmower because you'll break your windows with the flying rock. What a cruel joke! LOL!
EmmettO Marsh3 years ago
We put down that black weed barrier fabric before putting down gravel and it's held up well. Weeds will root on the rocks themselves, but they're few and easy to pull out. Also if you're not chemical squemish, a $14 jug of round up goes pretty far. I tried avoiding it but when my driveway started to sprout plants that will kill my wife (allergic) I got a jug and went to town on all the places that I'd been trying to suppress weeds mechanically.
Marsh (author)  luvit3 years ago
I actually have a lawn out front. Now that I have a mower, maybe I'll put one out back too.
luvit Marsh3 years ago
whoa! people can have 2 lawns? i wonder if rich people have side lawns..
Stupid people have side lawns. (What were we thinking?!) We had a sidewalk and a driveway that also needed mowing, because they were very old and full of cracks.
Would it be possible to get the schematics of the full circuit? You have a small schema of the "solar battery goes here", but you lost me with the cigarette lighter circuit.
Marsh (author)  TinkerWorkshop3 years ago
The full circuit is there. This unit doesn't use the cigar lighter plug. It was only shown to indicate the voltage regulator contained within...which we did not use.
Ok then I am unconfused. Thanks! Would it be possible to run a cost approximate? mostly I am asking about the land-mower.
Marsh (author)  TinkerWorkshop3 years ago
It's pretty comprehensive and all of the info you're looking for is there. Some of it is only on the photo notes so be sure to look at all the pics and mouse-over to read the associated notes.
talonts3 years ago
A few comments: 1 - The wiring could be cleaner/shorter if you rotate every other battery in the pack, so the +- jumper is very short. 2 - most solar panels have diodes built into them to avoid reverse flow already - if your panel screws together, open it up and check it before wiring. 3 - I'd recommend using Velcro to hold the panels on when not in use, and removing them while cutting - panels aren't really designed to be bounced around on a mower, even the ones made for charging cars. The shocks from occasionally hitting rocks or twigs will shorten the life of the panels. Better to remove them while in use. It also allows putting the panels in a better location for sunlight, as you noted in comments later. 4 - if you make the panels removable, cut the plugs from the panels, and use a 4-pin Molex plug to attach both. Molex plugs (ones with release tabs) will come apart easier than the plugs the panels in the 'ible have.
Marsh (author)  talonts3 years ago
Connecting and disconnecting are precisely what I want to get away from.Keep checking back. I'll post updates when it dies or develops any problems.
thebriguy Marsh3 years ago
You might consider a charging pad you just push the mower into and it charges - Either plugging it in when you push it in or make the contacts somewhere underneath so when it's positioned right on the pad it charges. Just some ideas. Thanks for the 'ible.
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