Solar Lawn Mower!

Step 15: There it is!

It works and really works well. I've been mowing my lawn every day for three days at the mower i fully charged every time I turn it on. All I need now is a lawn.

Comments

[Captain John]

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?

[vmod32]

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]

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]

It takes a week to recharge the mower for it's next use.

[Marsh]

These panels keep the batteries charged and ready all of the time. They're not very powerful. They probably won't overcharge it.

[vmod32]

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.

[patenaude]

I'd be worried that if you left it out for long periods (weeks->months), that the panels would eventually cook the batteries.

[Marsh]

time will tell.

[sbeazley]

Let us all know when/ if that happens. Would be good info.

[rhackenb]

I have this Toro mower. I've gone through two sets of batteries over 5 years. When I need to replace the batteries, I buy them from Toro. Instead, I get two 12 volt batteries from Batteries Plus or some other dealer. The cost is usually around $100 for the pair. I glue the batteries and wire them in series so that I get 24 volts. You say that the batteries you get cost $18. I wonder what the physical dimensions are and the amp hour rating. The two batteries that I use fit perfectly into the mower without any extra space. The batteries you use must be thinner. I appreciate the detail you have gone to in designing this. It taught me some lessons on electrical design. However, I'm not sure if the purpose is to charge the mower without having to plug into a wall outlet. If that's the case, a much simpler solution might simply be to plug the solar panels into an inverter and then plug the mower into the inverter. We actually use this solution to charge other battery powered devices such as drills at a shed we have that is not connected to the grid. See http://www.instructables.com/id/How-to-mount-a-solar-panel/.

The real benefit to me would be if the solar panels actually extended the current charge of the batteries while I am mowing.  Do you think these two panels would be sufficient to extend the charge in any meaningful way.  For example, could I mow an additional 30 minutes?   If not, the downside of the design is that the extra weight of the panels will make the mower even heavier to push.

Very good instructable.

[Marsh]

The replacements I used are made by Powersonic and they are exactly the same size and rating as the ones that came out of it (presumably the originals.) The idea was that I would never have to plug it in. I just park it on the back 40 and it's ready any time I need it. It runs for well over half an hour even if the grass is wet. I mean, I'm done in 25 minutes and the charge indicator is still reading full. Your batteries should last longer than that. They're probably being over charged by the on-board charger.