MAX Watts for DC power inverter?

[AllGoodHaywood]

I have an 05', anyone have any idea what is the largest Inverter I can get without draining the batteries while idleing?

 

[JFaughn]

This kind of a can or worms , 1st the alt. generaly is not charging to speak of at an Idle , should lock the throdle at about 1,300 RPM .
Next is your limited by the connection , the higher the amp load the closer to the battery & the bigger the cable you need to handle the current .
You may want to start with a differant ?
What is it that you want to run , some of the small cigarett lighter inverters [ 1,000 watts or less ] a 1,000 watt inverter is going to pull about 83. 33 amps at max load and will heat up and burn the wires in short order .
I'm not sure but the lighter is going to be fused at 15-30 amps .
Think about your batteries like a fuel tank , theres only so much in there , if you draw it out at a slow rate then you can have a small fuel line and it will take longer to empty , if you mod a truck for sled pulling you'll need larger lines and a hole lot of other stuff , and burn up fuel at a much higher rate .
You may want to put in deep cycle battery with a battery isolater , if you want to run almost any load for a length of time .

 

[Nate]

More like ~72 amps for 1000 watts. 1000/13. 8 = 72. 46

 

[AllGoodHaywood]

Thanks John but that either too technical or not technical enough. I was hoping to be able to get away with a 5K power inverter instead of a diesel genset in the back of my truck. Mostly just running power tools at job sites (chop saws, drills, stereo, and so on).



Do you know anyone that has a 3-5k inverter hooked up without problems? They said I would need a 1/0 line, pretty Fu**** big, but I am sure they are correct. My bigger concern over routing the wire, was starting the truck!

 

[seemore]

I'm thinking a 5kw inverter would pull about 400 AMPS!!! I'm pretty sure you would need a battery at least 10 times the size of the two truck batteries!! I don't think there is any way the truck's altenator could put out enough power.

Someone please correct me if I'm wrong.

 

[ENafziger]

Like has been alluded to before, voltage output of an alternator doesn't change much with rpm, but the current output does. At idle condition, I believe 30 - 40 amp alternator output would be the best you could hope for... and if you had the high-idle feature enabled and could "idle" at 1500 rpm, you may be able to expect 90 - 120 amp output from the alternator. In order not to drain the batteries, you could not draw more current than this from them continuously. Assuming around a 100 amp output idling at 1500 rpm, that would equate to running about a 1400W inverter... and factoring in efficiencies, would provide around 10 amps of usable 120 volt AC power.



Again, these of course are rough estimates, but hopefully give you some range of realistic output for continuous use. Alternator output will also vary with temperature, and placing an increased load on the alternator for extended periods may shorten its life as well. A sizeable power tool may pull 15 amps, and you may get away with intermittent use... but the upgrades required to achieve 5kW of continuous power through an inverter would probably not be as practical or efficient as purchasing a genset unit. Hope this helps... Eric

 

[JFaughn]

Basicly has been said , in order to do what you want , the batteries & electronics invoved would take up about half the bed of your truck
And the cost would be [ at 5,000 watts , you should also have 220vac] almost duable the cost of a Miller welder/generator , gas/$3,000 ,
then you may well get the diesel , welder/genset , about $7,000 .
It can be done , I've been into the alt. energy for about 30 yrs. , and avarge house , will cost min. $25,000 , with rebates , ect. you get money back & it pays for its self , but without being hooked up to the grid you can not get any rebates/ect.

 

[Hoefler]

Buy a belt driven generator, and mount it to the engine. Or if you have a PTO option on your transmission or transfer case, drive it from there.

 

[MChildress]

The new Miller Bobcat gen/welder is 10,000 watts I just bought one last year a little under $3000 for gas. My older 200 le Miller is 5,000 watts but does it at 1800 rpms. The newer ones make power at 3600 rpms. Its a little louder.