Inverter size

[schmism]

if you were going to add an inverter what size would you go with?

lets say general tool use, (only one at a time) skill saw, recip saw, drill, drop light, dremel....

anyone ever rigged up a heavy duty inverter to run off the pto? say a LARGE 24 v alternator runn off the PTO with dual deap cycle batts and a 1500 w inverter on a carryall or something?

you wouldnt have to run the tractor all the time with such a setup.. but yet its portable and isolated from the tractors tinny alternator.

if not going with a didicated setup like the above how big of one would you try to mount on the tractor?

whats big enough for everyday use but not overkill?

 

[Donman]

"say a LARGE 24 v alternator runn off the PTO with dual deap cycle batts and a 1500 w inverter on a carryall or something?"

Inverters are notorious battery power hogs and are at best 90% efficient, and should not be used at full time duty cycle. With the added up cost of the above - batteries, inverter and pto alternator, - you would be ahead with a pulley driven AC generator and then you could also use it for back up power for your house.

 

[Gryantaylor]

if you were going to add an inverter what size would you go with?

lets say general tool use, (only one at a time) skill saw, recip saw, drill, drop light, dremel....

anyone ever rigged up a heavy duty inverter to run off the pto? say a LARGE 24 v alternator runn off the PTO with dual deap cycle batts and a 1500 w inverter on a carryall or something?

you wouldnt have to run the tractor all the time with such a setup.. but yet its portable and isolated from the tractors tinny alternator.

if not going with a didicated setup like the above how big of one would you try to mount on the tractor?

whats big enough for everyday use but not overkill?

I've used a 700 W continous 1400W surge inverter for small, infrequent jobs. It will run a small electric weedeater for ~30 minutes off of a garden tractor battery and I can use it to power the electric chain saw but its right at the limit. It will power the skill saw just fine unless the blade binds then it overloads.

We bought the inverter about 5 years ago and 700 W was as big as they got without big $$$$. If I was doing it again today I'd get at least 1000W continous to prevent the overloads when the tools startup or stall.

As far as the charging system goes, I haven't upgraded the charging system on the cub cadet, we just installed the largest battery that would fit and run the tractor at ~1/2 to 3/4 throttle while in use. I've never run out of power during a small job. (large jobs we use the generator). but I will put the tractor on a trickle charge overnight just to help it recover if were using the inverter a lot.

For small jobs, cut down one branch, make 5 or ten cuts with the skill saw, weedeat a few small areas, etc. its great. If your looking for continous power for a 10 hour work day a generator would be far more efficient. At least thats my 2 cents.

 

[RonMar]

Watts is Watts regardless of the power source. Power in watts is equal to voltage times current or P= I times E. This is actually Volt Amps or VA which dosn't take into account power factor for inductive cuircuits but is close enough for estimations. 1000W divided by 12VDC = 83 amps of current draw from the battery. A 12V 40AH battery will be dead in less than 1/2 hour at this rate, especially after you factor in the inverter efficiency(or lack of) and the losses of drawing the current from the battery at this high rate(makes a lot of heat). It is also hard on the battery and shortens it's life to draw at this rate. That same 1000 watts drawn from the wall outlet in your home would pull 8.3A. If you are running inductive loads such as power tools, they draw a good portion of their energy from the peak of the sine wave. A inexpensive square wave or modified sinewave inverter will lack a bit of power for motors and therfore will require more energy from the source to run them and they will lack their peak rated power and will stall easier.

For short term use, you can get away with this but I wouldn't do a lot of work like this. Most tractors, having partly been designed by accountants are not known for their alternator output Heavy inverter use on their stock electrical system will shorten it's life also.

An alternator driven off the PTO to power a bank of batteries could be made into a more robust system. You would however need to gear up the alternator to an acceptable RPM to get a meaningfull output from the 540 PTO RPM.

If you are going to go to the trouble of building the inverter setup, I would reccomend the best of both worlds. Since you need to build up the drive for an alternator at an increased speed anyway, why not put together a small PTO AC generator. Use this with an off the shelf battery charger(AC to DC) and charge a small bank of four 12V batteries(48V total, lower draw per battery, more efficient and longer battery life). This in turn could be used to power an inverter. That way, you have the intermittent use available from the inverter without the tractor running all the time. You have a larger generator for if you need to power a larger load such as a small welder or air compressor.

This whole setup might also come in handy during a power outtage. The generator could power basic home needs such as well pump, refer and freezer and charge up the batteries during the day/evening. The batteries and inverter could provide small ammounts of on-demand power(lights, radio/TV) during the night and in the morning without the need to go out and crank up the tractor.

 

[Buckeye_Jim]

My company has 5 service trucks and we have outfitted two of them with auxilliary batteries and 1500 watt inverters. That will drive a small jack hammer, or a skil saw, drills, etc. Bought the inverters at Truck stops for something like $200. We added a battery isolator so that the truck battery get's topped off before charge goes to the aux. battery. Pretty happy with the setup. I am also involved with amateur radio and these cheap inverters emit interference with our sensitive receivers. My employees also seem to use a generator as much at the inverters. They can move the generator to the point of use and park the truck elsewhere. I given you a few more things to consider. Good Luck, Jim.

 

[schmism]

on what frequency range? IM a ham KC0TXH, and ill have much more of a setup out at the property in the comming years than i currently do in the city.

my load calcs go a bit diffrent

yellow top optima's go for about $120 a piece at 55 Ahr (2) of those and your looking at 110 Ahr.

assuming less than 100% max load (on a 1K inverter), say 500W continous, is 41 amps or 2+ hrs run time.

again my intended use isnt continous multi hr use, simple fix it jobs in otherwise powerless locations.

if i get creative i might be able to sqeeze multipul odyssey batteries and an upgraded alternator on the tractor.

 

[Soundguy]

For small jobs I've used a 500 or 700w inverter tied into my tractor's electrical system.. mind you.. those two tractors have big monster batteries.. the long ones.. not car sized batteries. I've had good luck running a power drill and an electric pole saw as long as i didn't load it up. Did run a skill saw.. but was only cutting 1/2" material.. and only a few small cuts.

If I were looking for more use.. I think I'd get one of those chinese or cheap generators that kick out like 2500 or 3250 w and are about 199$ to 299$

That .. or I'd get a pto generator.

I picked up a 12.5kw pto genny.. and it runs pretty much everything i need.. including a big arc welder... plus I can have backup power at the house or farm during storm season.. as long as i don't mind hearing a diesel drone away during power usage..

Soundguy

 

[schmism]

If I were looking for more use.. I think I'd get one of those chinese or cheap generators that kick out like 2500 or 3250 w and are about 199$ to 299$

That .. or I'd get a pto generator.

Soundguy

Ill likely have a pto generator at some point, and im not real intrested in yet another engine to maintain. Nothing like having the genny sit for a year, pull it out for a "quick" job and spend 30 min trying to get it started

was leaning toward this one
Amazon.com: Xantrex Technologies XPower Plus 1,200-Watt Inverter #813-1050: Home Improvement

i know xantrex makes quality inverters, and i know this version is still a modified sign wave version....

or something more portable, easyer to permantly mount on the tractor out of the way instead of huge setup....

Amazon.com: Xantrex Technologies XPower Plus 700-Watt Inverter #851-0700: Home Improvement

 

[Coyote]

For that kind of money, I'd just get a Honda 2000 Watt generator. Small, quiet, portable.

 

[shaley]

One word:
Peukert's Law
OK that's two but hey.
It is real, and real enough that Xantrex makes a mirco processor controlled battery gauges that use the factor in it. I've never been on a small boat that did not have battery issues at least once a season except when they had a gauge such as the Xantrex Link 2000.
Peukert Law states the more current draw from a cell the less available AH you will have. The stated AH capacity (group 24, 27, 30 etc.) is at a stated draw down current and it isn't very high at that.

If you are not expecting to use the inverter at high current then it will be OK.
I have a Xantrex 1000W in my truck and it would run both diesel batteries down over night while running only a small chest freezer at 300w.

See this Wikipedia link.
Peukert's law - Wikipedia, the free encyclopedia