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Up Topic Welding Industry / Welding Fundamentals / How to turn your truck into a generator
- - By ssbn727 (*****) Date 11-06-2012 02:05 Edited 11-06-2012 08:51
I found this article and thought "hey, maybe some of the fellows in here may want to do this, or get some idea's from this layout for their own trucks...
They also may want to install this on some of their other truck that usually don't have welding machines on them and may come in handy in a pinch for them...
Or to add it to their existing trucks for even hope this someone.

You're right 99205! somehow I got the other url instead when I copied and pasted er rather, attempted to paste it here... Here's the correct url link:

Thanks 99205

Parent - - By DaveBoyer (*****) Date 11-06-2012 04:20
I couldn't get the link to work.

Is this using the vehicle alternator?
Parent - - By DaveBoyer (*****) Date 11-08-2012 01:48
Something to keep in mind is that a 1500 watt load on an inverter will pull 150 amps on the 12 volt side.
This will drain a battery shortly, even with the engine idling.

Normal alternator amp ratings are done on a cold alternator at 5,000 RPM alternator shaft speed.

Alternators heat up rapidly under load, and the output falls way down.

Typical vehicle installations provide a 1:2-1:3 belt ratio, so alternator shaft RPM at idle isn't nearly high enough for the alternators to provide rated output at idle.
Parent - - By ssbn727 (*****) Date 11-08-2012 20:58
Even if you do this Dave???

Adding a 100Ah valve regulated lead acid (VRLA) absorbed glass mat (AGM) battery is optional. It adds a few hundred dollars to the cost, but it helps prevent alternator overheating and helps maintain the voltage under heavy loads. Add an isolation relay at the same time to prevent draining your main battery.

Res pectfully,
Parent - - By DaveBoyer (*****) Date 11-09-2012 04:03
I used an 1800watt inverter when I was on My boat. I had a 645 amp hour battery bank, 6 golf cart battetries in a series/parallel setup. This worked well, I cooked with a toaster oven/microwave combination, an electric fry pan and an electric cooker/fryer.

A meal like lasagna with toasted garlic bread required about 120 amp hours @ 12 volts. My normal evening 45 minute engine run cycle would not put all that energy back in the batteries, You need to put in 120% of what You took out. By the end of the next mornings engine cycle, the batteries would be pretty well charged.

Now for the rest of the story... I used an alternator rated at 195 amps cold/165 amps hot. This had 2.7" diameter puleys. The engine had 9" diameter pulleys running this alternator with (2) 1/2" [A] belts. The regulator would limit the amperage going into the battery bank to 135 amps, the proper amperage for this size bank. The voltage was set at 14.6 volts for bulk charging, and 13.4 volts for float charging. The engine/alternator combination would make 135 amps at 1000-1100 RPM.

You won't get this sort of performance from a stock truck charging system.

If You have an oversize single battery in Your truck, it may have 100 amp hour capacity. You add another 100 AH, so You have 200  AH. About 75% of this AH capacity is usable. 150 AH@12 volts is 1.8 KWH The inverter is about 93%-97% efficient at mid load. This gives You 1.71 KWH of 120 VAC above whatever Your truck charging system can support.

This is fine if You are running power tools while building a remote project, as the load is not continuous, altho it may be high at times.

Where the problem lies is when You have continuous loads above what the truck charging system will support. In that situation, You are using energy stored in the batterys, and that is a finite ammount.
Parent - - By ssbn727 (*****) Date 11-09-2012 19:58
I understand what you're saying now Dave...

Don't use it to cook, or anything other situation where a continuous load is required...

It will work fine when running power tool that don't require a continuous load.

This is only for someone that wants to be able have an ability to run power tools on a limited basis off their truck, but not to run anything that requires a continuous load.

Pretty much cut & dry Dave if it were explained in the manner you did! :roll::wink::cool:

Parent - By 803056 (*****) Date 11-10-2012 06:14 Edited 11-10-2012 06:17

That’s a great link. There are a lot of people in the PA, NJ, and NY area that could use that information. A little skill with hand tools can go a long way in making life comfortable. None of it works without fuel. I guess that is the weak link – fuel.

As mentioned before, I used a small 750 watt inverter during last year's snow storm to recharge my flashlights and to run the circulator on my wood boiler. It was fine for an emergency, but it didn't have enough power to run larger motors like the fridge, but we had plenty of snow to stuff in the fridge to keep things cold.

I had given some thought to installing the 1500 watt inverter permanently in my van for aux. power, but running cables from the engine compartment to the rear of my van would have produced too much of a voltage drop. The inverter needs a certain minimum voltage to operate and the voltage drop would have been too much. By the way, the larger inverter went up in a puff of smoke when I needed it most during the snow storm. Moral to the story: keep the cables between the battery bank and the inverter as short as possible to reduce the voltage drop. Also, the amperage draw on the battery / alternator is very high. You are converting 12V to 120V, so even if there were no losses, the amperage draw on the battery would be at least 10 times greater than the amperage provided to the output terminals of the inverter. The idea of two or three batteries is a great idea to minimize the load on the alternator and still provide peak power for short durations.

Dave, as always, provided some great insight.

I like the inverter system. It is cost effective and much less costly than a generator for emergency use. There are limitations, but if it can keep the boiler or the furnace and the fridge going even a couple of hours a day, it could mean the difference between comfort and barely surviving.

I opted for a generator for my wife. Considering the time I'm on the road, the generator is easier for her to handle when I'm not around.  

Best regards - Al
Up Topic Welding Industry / Welding Fundamentals / How to turn your truck into a generator

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