EcoRenovator - View Single Post - DIY battery electric push mower (cordless)

Daox · 08-16-11, 11:22 AM

For a while now I've considered making my own battery powered push mower. The electric riding mower I have is great and I love it. But, it can't get everywhere and I end up using the weed wacker to mow areas larger than I'd like. I'm not ready to pull the trigger and start making one, but did want to start a thread to collect ideas and improve the design. I think it is entirely feasible to design a DIY battery powered push mower for less than the cost of the cheapest brand new gas push mower. I'd also like to use as many off the shelf parts so that it is easy for others to replicate.

I looked up the price on lowes.com and saw their cheapest mower is about $150. It doesn't have very good reviews either... In any case, the goal will be to keep the price under that.

So, lets start looking at possible parts.

mower
This is the easy one. Find one for free! There are PLENTY of dead mowers out there that people are throwing away all the time. Put an ad on craigslist.org or freecycle.org. Someone is sure to be happy to have you take their 'junk' away.

motor
I've been looking at electric scooter motors. They're very low cost, about $0.10 per watt. I think a 300W motor would do just fine for this application, so you'd have to pay a whopping $30 for one. Most of these motors are 24V. If you go to a higher wattage motor you're probably looking at 36V motors.

batteries
For batteries, you're stuck paying whatever they're going for unless you're like MetroMPG and know people. The sealed lead acid batteries seem to ideal for this setup as you can get them in many different capacities. What you go with is completely dependant on how much run time you need. For me, I honestly only need 5-10 minutes, so two 7Ah batteries would probably be more than enough.

charger
Again, scooter chargers are incredibly cheap. You can get a 24V charger for $15 shipped off of ebay. It is of course a cheap Chinese made (what electronics components arent though) charger, but it will work well for the application.

blade to motor adapter
This is the only thing that I'm having a bit of trouble finding. I'm still looking for ideas. Obviously, I'd like to keep this as something you can easily make, or buy for cheap somewhere. Its also a pretty critical part since its holding a sharp steel blade that will be spinning at about 2500 rpm!

power switch
I think a ~30A switch from radio shack or whatever local electronics store will do just fine. It should cost about $5 would be my guess.

08-16-11, 11:22 AM	#1
Daox Administrator Join Date: Aug 2008 Location: Germantown, WI Posts: 5,525 Thanks: 1,162 Thanked 374 Times in 305 Posts	DIY battery electric push mower (cordless) For a while now I've considered making my own battery powered push mower. The electric riding mower I have is great and I love it. But, it can't get everywhere and I end up using the weed wacker to mow areas larger than I'd like. I'm not ready to pull the trigger and start making one, but did want to start a thread to collect ideas and improve the design. I think it is entirely feasible to design a DIY battery powered push mower for less than the cost of the cheapest brand new gas push mower. I'd also like to use as many off the shelf parts so that it is easy for others to replicate. I looked up the price on lowes.com and saw their cheapest mower is about $150. It doesn't have very good reviews either... In any case, the goal will be to keep the price under that. So, lets start looking at possible parts. mower This is the easy one. Find one for free! There are PLENTY of dead mowers out there that people are throwing away all the time. Put an ad on craigslist.org or freecycle.org. Someone is sure to be happy to have you take their 'junk' away. motor I've been looking at electric scooter motors. They're very low cost, about $0.10 per watt. I think a 300W motor would do just fine for this application, so you'd have to pay a whopping $30 for one. Most of these motors are 24V. If you go to a higher wattage motor you're probably looking at 36V motors. batteries For batteries, you're stuck paying whatever they're going for unless you're like MetroMPG and know people. The sealed lead acid batteries seem to ideal for this setup as you can get them in many different capacities. What you go with is completely dependant on how much run time you need. For me, I honestly only need 5-10 minutes, so two 7Ah batteries would probably be more than enough. charger Again, scooter chargers are incredibly cheap. You can get a 24V charger for $15 shipped off of ebay. It is of course a cheap Chinese made (what electronics components arent though) charger, but it will work well for the application. blade to motor adapter This is the only thing that I'm having a bit of trouble finding. I'm still looking for ideas. Obviously, I'd like to keep this as something you can easily make, or buy for cheap somewhere. Its also a pretty critical part since its holding a sharp steel blade that will be spinning at about 2500 rpm! power switch I think a ~30A switch from radio shack or whatever local electronics store will do just fine. It should cost about $5 would be my guess. __________________ Current project - To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts. To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts. & To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts. Last edited by Daox; 08-16-11 at 11:30 AM..