Electric Inverter Run off Tractor

Joe1 · Mar 3, 2012

I have a 770 John Deere with a 20 amp alternator. I want to be able to run an electric pole saw (8 amp) and some other small electric tools by hooking up an Inverter that would develop probably 1,500 watts continuous power. I know the 8 amp 110 volt motor will draw about 960 watts ac or about 80 amps DC. The saw would only run for a minute or two at a time. A 1,000 watt inverter would be close to the max draw and would probably not last too long at that rate.

I also do not want to hard wire the inverter to the tractor if I can avoid it. I would like to be able to place the inverter in the front of the tractor with alligagtor clips to the battery thru the grill opening (which I would remove or open). I don't want the inverter full time on the tractor as it will only get dirty and fail earlier, hence the alligator clips.

I would be running the tractor at rated rpm while using the saw because I would also be running my 5" capacity bearcat chipper/shredder at the same time.

In theory it should work, but it seems like a heavy draw on the engine battery. I've also be unable to find alligator clips large enough to handle the wiring for an inverter. The only thing I though would work would be to buy a set of jumper cables, cut them to about 2' lengths and add "eye" attachments at the othe end to connect to the inverter.

Internet research doesn't seem to come up with any reliable inverters under about $300.00.

I'm trying to avoid buying yet another implement with a gasoline engine and still be able to use the electric power for drills, etc.

Any suggestions would be a great help, so thank you in advance.

zzvyb6 · Mar 3, 2012

I'd probably replace the 'current' battery, with an RV or electric boat battery to ease the draw down.

I run all my high current electric stuff (including 220v stuff, off the outlets on my PTO alternator. For example I have a Stihl electric pressure washer which makes a great tree sprayer. I hook up the alternator, put a 140 gallon horse tank in the front bucket with a drain line into the pressure washer.

Only complaints so far are from mosquitoes and gypsy moths. I used to run my 110v hedge trimmers out at the road this way too. Then I bought a 24v battery powered one because other members of the family got into it.

A decent inverter to handle your load may be as expensive as a new 12 - 15kw pto alternator. Used farm grade alternators around here go for $800 - $1500 at auction or on Craigslist. I got my 50kw Winpower at an auction. You have enough power to run it (in spite of what 'they' will say). In fact, I made an adaptor to run my 540 rpm Winpower off of the front 2200 rpm pto shaft of my JD-F935 diesel lawnmower. I believe its about the same motor as you have in your 770 (22 hp ?).

Joe1 · Mar 3, 2012

Thanks for the response. I've got about 25 hp and 20 at the PTO. I was unclear in my message about the set up. I run a PTO driven chipper and would use it at the same time as the tree trimmer, thus the rated HP rpm while using the trimmer.

I certainly wouldn't need anything as large as you described. At that price, I'm into a new 2kw Yamaha or Honda generator.

Good point about the battery. There is room for a size 27 or evan a 30 under the hood.

I need to do more research. I'll look into PTO generators.

MarkOnTheRiver · Mar 3, 2012

I have been using an inverter setup for over 6 years now. It meets the same power requirements you stated you will need. I have a barn far away from the house without any power, so I hook it up whenever I need to run the grinder, blower, or a small air compressor for tire inflation. The battery used is the one for my Kubota L3400. I can use the grinder to sharpen the bush hog blades along with the blower to clean the tractor and Bush Hog without running the tractor to keep the battery charged up. It's a big plus for me to have power without the drone of a generator, not to mention yet another piece of equipment to maintain.

Here's what I have and the current cost is less than $300.

- TrippLite PV1000FC (non longer in production), current equivalent - PV1000FC (Tripp Lite PowerVerterｮ 1000W Compact Inverter with 4 Outlets (PV1000HF)). The difference physically is the PV1000FC uses a copper coil and the PV1000FC is electronic. So the difference in weight is 20 lbs vs 6 lbs

- 100 Amp Alligator Clips and cover - Automotive Clips, Battery Clips

- 4 AWG, 10ft length, cable kit - [ame=http://www.amazon.com/gp/product/B001550DVU/ref=oh_o03_s01_i02_details]Amazon.com: Cobra CPI-A4000BC 4-AWG Heavy-Duty AC Power Inverter Cable Kit: Automotive[/ame]

Egon · Mar 3, 2012

You might consider a deep cycle battery hooked up to the alternator with a one way switch so it's isolated from the tractor battery system.

Soundguy · Mar 3, 2012

HF has cheap, big inverters.

you can get large 2 pole DC to DC molex type plugs for quick connection..

storage battery will handle the load.. alt won't like it.. but... i imagine you will get plenty of use out of it before an early failure would occur.

soundguy

Doppelgangar · Mar 3, 2012

If you are doing what you want Put a larger Alternator on your tractor.

60 or 80 Amp Alternator would keep the charge and then extend the life of the battery in the long term. (second hand from a wrecker )

Or you could go the other way and get a transformer for your generator.

If you try to run it with a 20 Amp Alternator you will chew through batteries.

Joe1 · Mar 3, 2012

Mark:

Sounds good to me. I knew I came to the right place asking on this net. As I read your post, you can use the grinder and blowe, etc off the inverter without starting the tractor. What is the size of the battery on your Kubota and what is the alternator output?

How do you attach the inverter to the tractor? I was thinking of making a wooden bracket that would slip into the suitcase weight hanger. That way the inverter is near the battery for a short run and out of the airstream for the tractor engine and not in the way of the loader so it would be mobile. I would imagine the electronic inverter should be cooler running than the copper wound one. Any idea the amperage draw on your grinder and blower?

Thanks.

Joe

CinderSchnauzer · Mar 3, 2012

Joe1 said:
I have a 770 John Deere with a 20 amp alternator. I want to be able to run an electric pole saw (8 amp) and some other small electric tools by hooking up an Inverter that would develop probably 1,500 watts continuous power. I know the 8 amp 110 volt motor will draw about 960 watts ac or about 80 amps DC. The saw would only run for a minute or two at a time. A 1,000 watt inverter would be close to the max draw and would probably not last too long at that rate.

I also do not want to hard wire the inverter to the tractor if I can avoid it. I would like to be able to place the inverter in the front of the tractor with alligagtor clips to the battery thru the grill opening (which I would remove or open). I don't want the inverter full time on the tractor as it will only get dirty and fail earlier, hence the alligator clips.

I would be running the tractor at rated rpm while using the saw because I would also be running my 5" capacity bearcat chipper/shredder at the same time.

In theory it should work, but it seems like a heavy draw on the engine battery. I've also be unable to find alligator clips large enough to handle the wiring for an inverter. The only thing I though would work would be to buy a set of jumper cables, cut them to about 2' lengths and add "eye" attachments at the othe end to connect to the inverter.

Internet research doesn't seem to come up with any reliable inverters under about $300.00.

I'm trying to avoid buying yet another implement with a gasoline engine and still be able to use the electric power for drills, etc.

Any suggestions would be a great help, so thank you in advance.

Not sure what your consider to be "reliable" but here is a listing of 1500W inverters - many around $125. As an example, there is a Xantrex brand on sale at a local auto store this week for $109 reg $ 179.

1500 Watt Power Inverter - Compare Prices, Reviews and Buy at Nextag - Price - Review

For your load I'd suggest going at least 1500W. Even for the 1000W size look at hard wiring to the battery, including a suitable fuse. If you don't want a permanent mount look for a suitable quick disconnect. Be aware many inverters will be in 85% range for conversion efficiency, so you need to factor that in when considering size.

A larger battery would probably be better, however, a lot will depend on how long you intend to run the tool and how long between duty cycle.

It's pretty much a math exercise based on battery capacity, load, duty cycle and charge, whether it will work for you. Keep in mind if the battery has 100 amp hour capacity only approx 1/2 that amount is usable. Part of your problem will be that starting batteries are made for high amp short time application, whereas inverters work better off deep cycle battery such as Golf Cart batteries or others designed for lower amp / longer time.