Grass Push Mower

Sounds like you're clearing land instead of cutting grass.

I don't have one of these, but from what I've read the motor is a brushed DC Permanent Magnet motor fed directly from the AC mains through a bridge rectifier at about 170 VDC. That makes it kind of tough to convert to battery power unless you're going to use 12-14 12 volt batteries in series to drive the motor directly. If you're going to go the battery route you'll need at least 1440 watt-hours of battery power for each hour you plan to mow.

The B&D mowers that are battery powered use a 36 V Lithium battery pack so it appears that they don't use the same motor. Not sure that it's worth the time, energy, and money to try and retrofit the one you have, but I'll leave that up to you.

I've seen battery powered mowers that you can buy off the shelf. Google (battery powered lawn mower). Black and Decker comes up as one of many. That is unless you are a DIY and want the fun of inventing your own version of this wheel.

I'm pretty hard on mowers too. Sandy soil, and lilac stumps do a number on the blade. The engines never die, it's the mechanical fatigue of the deck, and push handle. So I don't understand what you could be doing to the engine, unless you've removed the dust filter.

Dust goes through the filter (= a fine sponge), rocks and terrain hard hard on the frame too. Need to permanently patch up and weld the machine. (It starts with a new machine from the 10th use and I considered mine as being "upgraded and heavy dutied" already) The filter is far too small to coop for the work environment. Wheels every 6 months.

You might have to change the motor...

http://www.builditsolar.com/Projects/Vehicles/LeeMower.htm

Or you could just go to Lowes or Home Depot and get a 36VDC mower or maybe this one

Tks Joe.

That is the one I have with cord. (probably with different motor). A $299.00 machine, landed here costs:

299.00

Florida tax 6% 17

Pick up 25

Transport 60

============= 401

Tax 47% on everything 189

Brokerage fee 25

Total price landed: $615.00

This is why I sometimes come with crazy ideas. Thanks anyway,

Instead of rebuilding the mower, rebuild your outdoor electrical system. I have outlets all over my yard, so I can cut my lawns with a 75 ft cord, and use an electric chainsaw anywhere on my 0.6 acre lot, and well into a neighboring forest that is essentially abandoned by its owner.

In it's early years (15 or 20 years ago), I hit a large rock, which bent the shaft and physically broke the permanent magnets inside the motor of my Craftsman 120V mower, so I had to replace the motor. Since then it has never complained. I'm about to replace the cord, but the mower keeps on chugging! I do listen to the motor while I'm cutting, and slow down to an appropriate speed when the sound tells me I'm pushing too hard.

These universal motors that are found in consumer goods usually are series connected. This gives high starting torque.

To do the job in the same way you need 120 V dc. That would be about 30-35 lithium 3.7 V cells. quite expensive.

You can also test it with about half the voltage. Obviously it will work slower but it can do the job as the motor won't mind having half the voltage.

I'll have to tell you there is a tweak with this universal motor. If you vary the current through the stator you can vary the torque of the motor and if you vary the voltage of the rotor you can vary the speed. For this to be of any use you have to go to parallel connection.

I have both an old mower of this type and a battery powered mower that I got for $10 with a bad battery. Since getting the battery unit I have not turned on the plug in model once and thinking about it due to this discussion I will list the plug in model on freecycle today. The battery power unit go cheap or free if the batteries are bad. You like to dyi but what about just getting an older battery unit with a bad battery and restore it with a new battery and any other needed repair? That way you get the charger, controller and other parts which rarely go bad and the total unit is ready to go once you change batteries. The battery for mine cost 2 1/2 times what the mower itself cost but if you buy batteries to do the whole thing yourself you will spend more than that. I got my battery off the internet to avoid the cost of the 6Xmower it would have been locally. I looked at using NIMH cells instead of the original lead acid unit but the cost would have been more and the savings in weight was not that critical. Plus it would have been a lot of hassel. I really like the battery powered unit, it is one of the old ones with only 12 volts. The battery is located near the rear tires and balance point of the mower so you don't notice the weight of the battery. It works fine and will do all of my 1/2 acre lot but I rarely do it all in one day since I do other things in each area as I work and complete each area before going on to the next. The 36 and 48 volt units are better but I don't really need them. My units are quite old and B&D. I try to look for rocks before mowing and while mowing. I live in the west and find that it is better to water the night before mowing to keep dust down.

Now, if I could just find a cheap battery powered weed eater that would use the same batteries as my Ryobi battery powered tools, I wouldn't have to mess with gas at all. Ryobi makes a battery unit but it doesn't fit the Ryobi accessories like the tiller attachment that the gas powered Ryobi unit takes.

Maybe you could increase the size/capacity of your filter, possibly use an automotive filter and rig up a snorkel to get the air intake away from the source. I've thrown many rocks with my metal deck lawnmower and even more with my Honda (plastic deck) and haven't cracked or damaged one yet. I'd stay away from cast decks, but sheet metal decks will simply dent.

Back to the question of the electric mower you have. I just reviewed mine and am pretty sure it is a series motor. Try this. A series motor should run at any voltage up to the full voltage, just at a lower speed. Try hocking it up momentarily to a 12 volt car battery. Just a moment so if it is parallel you won't hurt the battery or motor. The motor should start with 10% voltage and run slowly. If that happens it is series. If it just arcs and doesn't try to turn then it is probably parallel unless there is a lot of friction in the bearings. I then have a problem with idea of a 120 volt, low amp battery being able to provide the amps to cut your lawn. As with many of the 4KW packages on the market for the Prius conversion to plug in recharging. They worked fine with 4KW lead acid but when the Venders started switching to LIFEPO4 they wouldn't work because of the internal impeadance of the battery. The 12KW will work but not the 4KW. I feel that you will run into this same problem with the idea of a 120 volt power pack. Although you said you didn't want to, I would advise a lower voltage battery with either an inverter or a step up DC-DC voltage converter. My thought is that the inverter from one of the older stand by power supplies would work great. My old standby power supply (which I never use now due to batteries in my laptop) uses 48 volt gel cells and kicks out 120 volts, 1600 watts for 4 hours. You can usually get these really cheap in thrifts shops and on Craig's List. I paid less than $10 for mine. Most of the weight is the batteries and case. The inverter is really small and light.

Wouldn't a hand held weed trimmer or even a push type work better for you than a mower. It would create a lot less dust so engines would last a lot longer on a gas powered one and no repairs to a metal deck and blades. Even though they are called weed trimmers they do cut grass fairly well. For the hand held , they do come with battery models , gas and electric. Pick a model and size that would suit your needs.

Push Type http://www.youtube.com/watch?v=Z_HgqbA4ZZw (Example)

Hand held (Corded) (Example)

The following link will show a few different models of the Push or Wheeled type trimmers

http://www.stringtrimmersdirect.com/weed/walk-behind-trimmers.html

And here is a Gas VS Battery Powered review

http://voices.yahoo.com/gas-vs-battery-powered-weed-whackers-5389619.html?cat=30

Good luck with whatever you decide..

Rescue

Thank you,

But holding that machine is definitely more work and the end result is less professional.

We collect the grass in a bag. The wires also don't last long in St Augustine grass. I use that to trim the edges.