Welding off two truck batteries

[tapwelder]

In my experience Welding off an inverter, then the standard Alternator will operate at a deficit and minimal weld time. I did see our public works dept. Operate a miller mig welder while installing a handrail. The workers did not know much about the power source. It was a big truck and i vaguely recall 4k watts.

[52 Ford]

In my experience Welding off an inverter, then the standard Alternator will operate at a deficit and minimal weld time. I did see our public works dept. Operate a miller mig welder while installing a handrail. The workers did not know much about the power source. It was a big truck and i vaguely recall 4k watts.

It'll definitely drain a battery pretty quick - but so would welding straight off them. You can buy a "high idle switch" or "auxiliary idle controller" to keep the battery charged. I've seen two types on diesel pickups. The more basic of the two steps idle up to a certain RPM and holds it - mostly for PTO stuff, I guess. The other kind varies the RPM to keep the battery charged. You see them on ambulances and trucks like that, that'll sit parked with a high electrical draw. Almost always diesel - though I don't see why you couldn't put it on a gasser.

My other thought would be a second alternator with a clutch on the pulley. Flip a switch to cut it on. Wouldn't need to be a large alternator, either.

Sent from my SAMSUNG-SM-G891A using Tapatalk

[Kpack]

Don’t know what a Modified Sine Wave inverter will do.

[52 Ford]

Don’t know what a Modified Sine Wave inverter will do.

Oops. Didn't realize I linked to a modified sine wave inverter. Thought that one was a pure sine... I guess I should have read where it said "Modified Sine Wave" in big letters.

That is an interesting question. I hadn't considered what that'd do to the arc. Probably not much on DC. I bet it'd sound a bit different running AC. I don't think it'd perform much difference in practice, though.

Sent from my SAMSUNG-SM-G891A using Tapatalk

[BMX Welder]

Just spotted this thing on market place for $300. It's the same Real Gear spool gun I run on my big mig for Aluminum. I think I got the gun with tweeco adapter on account for around $90. I also see them on Amazon, I would think you could add some battery terminals for less than another $210?

https://www.facebook.com/marketplace...54514688%22%7D

[FlyFishn]

Generator? Problem solved.

I do not intend to carry a generator so a full blown 120/240V welder is out for now.


Flux core with 24V should be doable unless i am missing something, and it would be the lightest, most portable solution. Wouldn’t expect a lot of welding in the field but if something breaks it’d be nice to be able to join it back together. Just a few inches of weld.

For what it is worth, I got a sine wave inverter (Xantrex) about 10-12 years ago. The reason I got it was to run RF test equipment in the field that needed 120v AC power. I had smaller inverters, but they were low power and modified sine wave. I needed something with cleaner power and as it turned out the one I got had enough power to run some lighter power tools. I used it for years for my "on-the-go" power - out of the truck, boats, you name it.

When I would run the inverter to power tools etc on projects I would connect directly to my trucks' battery(ies) or boat battery. For any real work it would drain the batteries too quick and either a way to recharge or a separate start-only battery was required.

About 4 years ago I was doing a ham radio event called Field Day with a buddy of mine. He owns 2x Honda EU2000i generators for his portable power (can daisy chain them for 2x the power also). I was impressed with them and ended up getting the newer version - the EU2200i - a few years ago myself. I use it all the time now. It is small enough to carry everywhere in my truck or SUV. I find it more convenient to use instead of opening the hood and clamping cables to the battery. Lastly - I have no worry of running out of power, or not having enough power. It will run all my electric tools, among other things, and it sips gas. So for working on projects for a few hours the generator barley uses any fuel. Can't say that about an inverter and vehicle batteries, not by a long shot.

If it were me - and I do a fair amount of on-the-go work without access to commercial power - I would highly recommend you re-think your thoughts on not wanting to carry a generator. Yeah, it is more gear. However, the versatility of one is very hard to beat. Having real AC power on-the-go can be a real game changer.

As for welding - you are going to need some good wattage from a generator to run any real welding capability. However, one thing you need to understand is Total Harmonic Distortion, or THD. There is a difference between an Inverter style generator (example - the 2 hondas - EU2000 and EU2200 - mentioned earlier) and a Rotary style generator (your constant 3600RPM speed engine driven alternator style - "screamer" style generator most people are probably familiar with). The Inverter generators typically have much lower THD than a rotary, by nature of design - they use a computer controlled set of transistors to "create" the AC sine wave. A rotary generator uses the rotation of the alternator to generate the AC sine wave - totally different process. Cheap rotary generators can produce terribly high THD. That high THD can kill computerized electronics - and inverter style welders constitute sensitive computerized electronics. The max THD that is considered "clean power" is around 4-5% THD.

Of course, if you had an old-school analog (transformer-based, not transistor/computer based) welder then it won't care about THD. However, considering weight/bulk vs welding capability - pound for pound you can't beat an inverter welder = ideal for portable.

As to the efficiency of generators and the ability to have good power output - Inverter style generators are by far more efficient and have cleaner power. However, they do have "start up" delay that can be problematic when trying to start an arc when welding. A rotary generator is better at that "instant power" as the engine is at 3600 RPM. There is generally less delay in the power hit when striking an arc than on an inverter generator because an inverter style unit has to tell the engine RPM to ramp up to meet the power demand, whereas the rotary is already "there" (it needs to open the throttle to provide more power, though).

The larger the wattage of the generator the less sag there is when you strike an arc. Same thing goes for start up loads of big motors like AC units, air compressors, and well pumps.

If you have 6kw running wattage (say, 7-7.5kw starting wattage) that is where you want to be for relatively heavy welding. That would get you plenty of head room on amperage available for welding. That would be 25 amps at 240v - way more than technically you would likely need, but that gets back to the arc start delay - the more head room you have the lower that start sag is.

If you look at what you can run off a household 15a outlet - there are a lot of 120v welders you can run off that type of power. However, you have to be able to supply good honest 15a at 120v. I have fought with this issue in the past many years - trying to run a 120v flux core machine off a garage outlet with lights, fans, and who knows what else powered off the same circuit. You can not get good power to a welder like this. The work-around is to isolate the circuit for the welder - get the welder on a circuit where, hopefully, it is the ONLY thing on the circuit (and if there is anything else - only very small loads like maybe a couple lights, but the welder being the sole load is best).

With that having been said, there are a lot of generators that will provide more than 15 amps of 120v power. There is a whole market for the RV crowd that is around this whole principal. RV's use single 120v power distribution, as opposed to split phase 120/240v as in a house. However, with the appliances in the RV's - microwaves, AC units, etc, etc - they need a lot more amperage than 15 amps. So you will find a lot of generators - specifically inverter style - that have 30 amp RV twist-lock receptacles on them (3 pin 120v only, not the L14-30 4 pin's) - units from about 3kw on up. These inverter units are very quiet and still quite portable.

That is where my recommendation is for a generator if you are going to try to weld in the field on your adventures - the RV class inverters maybe around 4-4.5kw. You will have the quietness of an inverter generator, the portability of an inverter generator, and more meat behind the power they can provide.

For what it is worth, my portable welder became an Everlast Powerarc 210STL stick/tig machine last winter. I have not had a reason to weld out in the field with it yet, I've had commercial power for it (240v - never run it on 120v - yet) the times I've used it. However, I am working on a light project right now so I can try to run it on the EU2200i just to see what it will do/where it struggles. The EU2200i is "clean power" (I'd say it is the epitome of a portable clean power generator). My large rotary is around 4% THD and I have no doubts I can weld off of it - it will push north of 60 amps @ 240v, that's enough to run my old Round Top harder than I'll ever have any reason to run it. We can run the whole house (including central AC) on it with no problems.

Good luck with everything. Off-roading is a good time, for sure. So long as you can "get out". And having portable power will give you a large edge up on being equipped. This past summer we took a wrong turn at my buddy's farm and got stuck in a clearing that was going to be host to an oil well about 30 years ago. The trail went down a steep hill to the clearing. The clearing was very soft and the tires sank. My truck is an F350 CCLB SRW with a fiberglass cap. Empty it is about 8500-9000lbs. I had it in 4lo and didn't even make it back to where the trail dumped us down in to the clearing. So I backed up trying to get room to get a running start. All I did was sink. On my "running start" I couldn't even make it up to where I stalled the first round. I happened to have my utility winch with me, but I didn't have all the rigging. I wasn't going out with the thought of "off-roading" - we were scouting a spot for camping, of sorts, for a few days that was high up on a ridge with regular vehicular access - but missed the turn. I did have 2" ratchet straps and tree saver straps. So we daisy chained what we could to hit what trees we could. The winch gave us plenty of extra pull to get past the sunk tires in the clearing and the slick wet trail where we couldn't get traction. Moral of the story - it pays to be able to "get out". Ya never know when you're going to get screwed.

[52 Ford]

I started carrying a 12V 3 ton winch in the back of my truck a few years ago. It's a winch made for a boat trailer, so I can put a handle on it and crank it by hand, too.


I hardwired my inverter and put it under the drivers seat. I can flip a switch on the dash to cut it on. I keep a compressor in the toolbox and the inverter has no trouble running it at the end of a 30 foot extension cord. I put some outlets in the cab that I can get to while I'm sitting in the truck, so I can plug in battery chargers or whatever else.

Sent from my SAMSUNG-SM-G891A using Tapatalk

[Oscar]

and inverter style welders constitute sensitive computerized electronics.

The more expensive ones will not run if the incoming power isn't clean enough. Cheap ones won't know the difference and try to run, and then let out the magic smoke. Also the more expensive ones are less sensitive to THD and are now more tolerant.

[Meltedmetal]

And here is another option for remote welding. Don't know if it lives up to the claims but here it is: https://www.weldingforless.com/produ...e9pg%3D.TvpuE9

[426hemi]

I’ve done battery trick a couple times, I didn’t have any way to limit the current and on one occasion I used a damn coat hanger as I didn’t have any electrodes. It’s got me home a couple times or at least out of the woods. I wouldn’t over complicate it. I highly doubt your going to be able to regulate the current and get good results as the voltage is constantly dropping as the batteries drain. Sure you could engineer something to give a great output from a couple batteries but at that point your better off with welding machine at that point.