Mobile Welder Comparison

So your out on the trail when it happens: the power steering mount breaks off the frame, the shock mount comes off, the steering arm cracks.   If you have not yet had a break on the trail that could use a bit of welding, you probably know someone that has.

So what's out there when it comes to portable welders?   For trail welding we need something that's portable, compact enough to fit into our already overflowing tool and parts boxes, and something that is going to work and get you off the trail.   

We went out and found 5 systems that fit into those category's.  Three of the systems are installed onto the vehicle, and two are portable units.

First are the vehicle installed systems, you can click on each of them to see the installation process:
There were two completely portable systems in the comparison, the GoWeld and the Readywelder.

The first thing we had to do was install the Zena, Premier and Mobi-Arc systems.  All three systems came with good instructions that were easy to follow.   You can see the detailed installations by either clicking on the welders name above or on the picture of the welder above.   

All three of the welding systems either came with new alternators, or they provided the necessary parts to modify the factory alternator for welding use.    If you replace your factory alternator with a new unit, your old alternator can be saved as a trail spare to get you home if you have a problem.

It should also be noted that by modifying electrical components of your vehicle, you risk voiding any warranty that you may have for the electrical system.   Check and double check you connections to make sure they are all secure and in the correct places!

Having never installed anything like this before I was not sure what to expect.   When I was looking at the wiring diagrams, all the wires and such it was intimidating!   I can, however, report that all of the installations were much easier than I expected.   All of the welders came with simple and easy to follow instructions, and even with little electrical knowledge I felt completely comfortable doing the installation on my vehicle.   If you have been considering installing one of these welders and this has been one of your major fears, I would urge you to download and read through the instruction manuals for that welder.   Its not as bad as it may seem!

The Zena unit was the first of the welders that we installed during this review.   It has the smallest control box of all the welders that we tested, about the size of a pack of cigarettes, which made for easy of mounting.

The Zena welder was the only one that utilizes a dual alternator setup.   The down side is that in a cramped engine compartment you may have to get somewhat creative to get the second alternator mounted.   Once you are over that hill, the installation is very quick and easy.   The extremely small size of the control box made up for the space that the second alternator took up.  

Modern vehicles have an extensive array of computers that control most aspects of the vehicle.  This is one of the reasons that the manufacturers normally advise against modifying the electrical systems.   Zena highly recommends using the dual alternator setup specifically for this reason.   

The installation vehicle was an 1986 Suzuki Samurai.  The AC pump had been slated to be converted to a air compressor, but we decided to use the space for the second alternator provided by Zena.   After removing the AC pump, the new alternator was bolted directly into the brackets.   Zena sent us a great selection different parts to aid in the installation.   One of them was the UB2 Universal Piggyback Bracket Kit.   First off let me just say WOW!   All of their bracketry was made out of aluminum, not stamped or bent steel.   The UB2 kit was an incredible piece of work, allowing a great number of possible mounting solutions.   They also had Add-A-Pulley kits so you could add an extra belt to an existing pulley to power the new alternator.

Wiring of the Zena was very easy and straight forward.   Since there was no need to tap into any of the vehicles existing wiring, it made for a quick installation.   

Zena also provided a vacuum actuated throttle control that wires into the control box.   It was attached to the gas pedal linkage under the dash.   

There are some big upsides to the dual alternator setup.  The first is when it comes to welding on your own vehicle.  With the other welders on the market, you have to be careful and reverse the polarity to weld on your own vehicle.   Because the Zena is like its own secondary electrical system you can weld on your own vehicle without reversing the polarity.   With the second Zena alternator, you have two separate electrical systems on your vehicle.

In dual alternator systems like our install it's also easy to provide power to a split electrical system, supporting high power demands like high power stereos, winches, extra lights, etc. separate from the main vehicle electrical system.   By doing this you are protecting the stock system completely from problems such as brown outs that can cause significant damage to the vehicle delicate electronic controls.

One of the great things about the Zena that was talked about during the testing time and again is that all of the controls are on the stinger (the clamp that holds the welding rod).   With this setup, you can lay under the vehicle with it running and everything fully hooked up and figure out how and where you are going to weld.   You may be trying to fit the stinger and rod into a tight place, you may be seeing how far you can weld before you have to reposition.   

Once you decide that you are ready to go, you need only to press the power button.  When the power button is pressed, the control box automatically raises the vehicle's throttle to welding speed and turns power to the stinger on.   You strike you arc and weld.   When you are finished, you let up on the power bottom.  The control box cuts power to the stinger and drops engine RPM back to normal.

The Zena vehicle speed control could also be wired to a separate switch and be used when you needed more power from the alternator for high demand operations such as winching.

While Zena has a variety of universal brackets, they have custom bolt on brackets available for most U.S made trucks.   In our installation, the bracketry for the AC pump that was no longer used provided a near perfect direct fit.

While not used during our review, Zena has control interfaces specifically designed to support all types of commercial arc welding: TIG/Heliarc, MIG/Flux Core wire welding, gouging/cutting, etc., and they also have under hood welding systems which can provide as much as 600Amps.


The Mobi-Arc came with a kit to modify the factory alternator so it could be used for welding.   We installed this kit for our testing and used the stock alternator. We then switched it out for a Northwest Power Products 160 amp model so we could see the difference between the two.   

To install the Mobi-Arc, we first used the provided kit to modify the factory alternator to allow it to be used for welding.   This was a fairly simple task, and the instructions were clear and easy to follow.   After the factory alternator had been modified, it was re-installed into the vehicle.

A spot was selected for the control box.   We made a simple bracket that would use existing bolts to mount the control unit to the vehicle.   The wiring of the Mobi-Arc was simple and the diagrams were easy to follow.   The included throttle control was installed and we were ready to go!

The Mobi-Arc unit is a completely solid state welder that is fully automatic with no switches, knobs or controls.   When you plug in your welding leads, all you need to do is strike an arc and start welding.    Until an arc is struck, the alternator continues to charge the battery as normal. When the arc is struck, the Mobi-Arc instantly breaks the connection between the alternator and the battery. This isolates and protects the vehicle's battery and electrical system. The alternator is then ramped-up to 38 volts open circuit which is optimum open circuit voltage for the welding process.  If welding ceases for more than 50 seconds, the Mobi-Arc will automatically ramp the voltage back down to an automotive friendly 14.5 volts and restore the connection to the battery.

Mobi-Arc also has a variety of optional items that can be added to the Mobi-Arc system.   Some of these include a Mobi-Power 110v module and a TIG welding kit.

After we installed the Mobi-Arc unit, we welded with it for a while going through about 6 rods.   It produced nice welds and was easy to use.   On test night we planned to weld with all the units side by side, but there was an unknown problem and we were not able to use the Mobi-Arc unit that night.    It took quite a bit to track down the problem, and as is the case with many electrical related problems it turned out to be something quite simple, completely unrelated to the Mobi-Arc unit.   When we spliced the wire on the Mobi-Arc harness to the keyed on power wire, the red ignition wire from the original alternator harness, we used a simple plastic quick splice.  

As can happen sometimes with these types of splices, the wire was cut and was loosing contact intermittently and caused a great deal of headaches.   All sorts of checks done and re-done, and finally it was corrected and everything was fine.   


The Premier Power Welder is not control free nor is it all solid state, but it comes standard with a few features that the others did not have.   

The first and most noticeable thing is that there is a 110V DC receptacle just like the plugs at home.   This can be not only be a life saver on the trail to operate items such as a grinder or drill, but saves money as the tools that you use at home can now find work on the trail.   The 100V DC plug will provide about 2300 watts for brush type motor items such as grinders and drills.   It will also operate items such as drop lights, toasters, coffee pots and blow dryers.  

The second feature that comes standard is the ability to charge a battery.   You can set the controls for charging and use the welding leads as charging cables.   While the system is not meant to be used to jump start another vehicle, it charges battery's as a much quicker rate, so a vehicle with a dead battery should be able to start on its own after just 2-3 minutes of charging.

We replaced the factory alternator with the alternator that Premier supplied.   This was an 160amp unit.  The Premier unit was a direct factory replacement that was easy to install.  

After the alternator was in, we selected a location for the control box.   The factory battery was replaced with an Optima yellow top.  The Optima was slightly shorter, and this allowed us to simply reverse the plastic battery tray and locate the battery under the fender slightly.   This gave us room to mount the control box next to the battery in the cramped Tacoma engine compartment.   All of the wires on the Premier Power Welder had tags on them that indicated where they would go, and connecting all the leads just took a few minutes.   After a check to confirm that everything was working correctly, I started to clean up all the wires and get them into looms and out of the way!   I ended up shortening the wires and removing the excess for a cleaner installation.   The wiring harness is about 6 feet long to allow for different mounting locations, but I really only needed 1-2 feet at best for most wires.

The included throttle control was attached to the fire wall and tied into the throttle linkage.   This will allow the throttle to be set at higher RPM's for welding, but also when you want a bit more power from the alternator for high demand applications such as winching.

To operate the Premier Power Welder, you first turn the master power switch on, and select low or high weld.   The control box is a basically a large switch.   When the master switch it turned on, the Premier Power Welder is isolated from the vehicles electrical system and battery, this is to protect the vehicles electronics.  The alternator is then in welding mode and the rod heat is directly proportional to engine speed, welding can start just above idle.   To adjust the engine speed, a throttle control is provided.   After the master switch is on, you can adjust engine speed until the needle on the units gauge is at the desired welding voltage, or in the recommended area on the gauge.

The Premier Power Welder has been around for just over 26 years now, and the design has not changed much.   There are some advantages to being low tech.  The primary advantage is that if the unit should malfunction, the end user can call Premier Power Welder and work with them to diagnose the problem.  At that point, the end user can then send the unit back for repairs, or simply perform the repairs themselves.


We met at a local welding shop where Tony was going to give us some feedback. We set up the Premier Power Welder and Zena and started to play!

The setup for the Zena is very simple, just plug the two leads in and you are ready to go.

Having complete control of everything right from the stinger was a great feature on the Zena.

The controls on the stinger are the power selection knob, the power button and the boost button.

The boost button allows the use of full power for starting arcs in difficult situations. Once the boost button is released, the power reverts back to the level selected by the power control knob.

The first welder Tony welded with was the Zena.   We started with a simple series of lines just to get a feel for the welder.  Tony welds all day long but he uses a large Miller wire machine, so the stick welding was a big change from the daily routine!   The first and most noticeable thing about all three installed welders was the sound.   All three of the the welders are high frequency units, and they have a very distinctive almost whistle like sound.

Tony welding with the Zena Welder.
To setup the Premier Power welder, simply plug the leads into the front of the control panel.

Next, Tony did some lines with the Premier.   The biggest differences between the Premier and the Zena was that the Premier seemed to weld a bit smoother, this may be because the Premier had a bit more power.  The Zena unit has an 150 amp alternator, and the Premier Power Welder has a 160 amp alternator.  Even the 10 amps seemed to make a noticeable difference.   With the Premier we played with both the high and low weld settings.  When on the high weld setting, you could see the heat from the deeper penetration on the back side of the metal compared to the low weld setting.

The first two lines from the Premier Power Welder (left) and Zena (right) , it was clear that both units were capable of producing quality welds.
The back side of the metal, with the line in the middle clearly showing the increased penetration when the Premier Power Welder was set on High Weld.

 They both were capable of nice welds, more than enough to get you off the trail in a pinch.    With a bit of practice, even the novice welder could use any of the three units and produce permanent welds.

Speaking of that novice welder, we wanted to see what someone that had no welding experience could do.   We had Warren Holybee come in to the shop were Tony gave him a 5 minute welding class, we then turned him loose with the Premier Power Welder.   

Warren gets his quick 5 minute lesson.
Warren doing his first weld with the Premier Power Welder.


Warren had no welding experience and had never even attempted welding before.  Once Warren got the arc started he was actually able to make a really great looking weld, quite a bit better than I was personally able to do on my first try!   Warren ended up doing a few welds with a few of the different welders.   The main thing that I wanted to accomplish was to show that with any of the welders we tested, I feel that a person with virtually no welding experience would be able to do at least a temporary fix that would get them off the trail.   I think that Warren clearly demonstrated that this was true.   

So at the end of the night we discussed the Premier Power Welder, Mobi-Arc and Zena, and what benefits they had to offer.   Here again, one of the things that everyone felt was great was the controls on the Zena.   With everything on the stinger, you never had to turn it on and off, and it was not live until you wanted it to be.   The extra features such the Premier Power Welder had to offer, such as the battery charging mode and 110V outlet were also nice.  The Mobi-Arc unit was didn't have any controls at all, so there was nothing to learn or know, just plug in the leads and start welding.   All in all we felt that it would be a hard decision to choose between the three.   It was suggested that it would be nice to combine all the units and create a fourth unit with all of the features they offered rolled into one!

Premier Power Welder
1yr alternator, 2 yr box
3 years on all components and accessories, with no restrictions on commercial use.
alternator amps as tested

Next we played a with the GoWeld and the Readywelder II.   Both of these units are not vehicle mounted, but completely portable.   While you can attach them to a power source, such as the Premier Power Welder or Mobi-Arc units, you can also run them on 2-3 standard vehicle battery's.  

To make sure that we were working with a level playing field, we contacted Optima and got 4 deep cycle battery's, 2 for each welder.   Keep in mind that it is not normally the case in the real world to have two brand new deep cycle battery's available, as you will see later in the article.   The other thing that will affect the welders real world use in the field is that you may not have two battery's that are the same size or condition.

At first both units seemed to have a lot in common, but when you looked a bit more the similarity's started to fade away.   

The Readywelder II was a very simple unit.  You hooked it up, you set the wire speed and you welded.   There were two lights on the gun, both power indicator lights.   The green light is for reverse polarity, the red light is for straight polarity.   

The Readywelder II has a plastic housing with the wire spool in the base of the handle.

To change the wire spool, you remove the red "T" screw and the two half's of the cover come apart as shown.   

The wire feeds through the handle and up to the roller motor.   

Click the picture to see a larger version for more detail.

There are three tension settings for the wire rollers, which you adjust by moving the spring clip into different slots.

The red piece towards the top of the gun is a roller release so you can feed wire through the rollers when you are loading a new spool.

With the Readywelder II you can weld until the battery's become drained.   There is no cutoff for low voltage, so as the battery's voltage decreases, so does the units performance.   

We found this out first hand with the Readywelder II while on the Rubicon trail.  While welding on a 4Runner's frame, the Readywelder II seemed to develop problems.   It didn't occur to the person doing the welding or the spectators that the battery's they were using may be dead, they hadn't been welding that long.  After fiddling with the unit for a bit, they figured it out.  At that point, one battery was so dead that it yielded only a click when placed back into the vehicle, the second battery was a bit better and was barely able to start the second vehicle.

This same scenario was repeated a year later on the Dusy Ershim trail when a Jeeps frame cracked.

The GoWeld was also simple, but had some refinements that made quite a bit of difference.   

To see the GoWeld users manual click HERE.

The gun has a different design, with the spool in the top of the unit.  There are 4 labeled lights on the front of the gun (yellow arrow): Power, volt +, volt -, and low batt.

Once the gun is hooked up to power, the power light comes on.   Depending on if you are using positive or negative ground, the volt + or volt - light illuminates.   When battery voltage gets too low, the low batt light will come on and eventually the onboard computer will cut off the welding process.  This allows you to charge the battery's up and not end up stranded with two dead battery's.


There are two dials, one for wire speed and one for voltage.   Voltage control has been changed and is all done automatically based on the wire speed, so the voltage knob is not used.

An optical sensor reads the wire speed around 675 times per second and automatically adjusts the welding voltage for a more consistent weld.   

Here is a really nice cutaway view of the GoWeld unit, courtesy

Any of the adjustments you may want to make to the GoWeld, or if you need to change the wire spool can be done by opening the top cover.

To change the wire you need only to open the cover and remove the spool.   You can also adjust the wire tension with the thumb screw on top of the spool (yellow arrow).

There is also a lever (green arrow, shown in the op position) that allows you to open up the feed rollers to easily feed the wire through and get it started.

Another of the differences between the two welders was the size of the cases that they were stored in.
Here you can see the two cases, with the Readywelder II on the left, and the GoWeld on the right.
Another angle, showing the size difference.
The Readywelder II was just a simple padded foam case.
There was room for a few extra spools of wire, the welder, all required cables and some spare parts.   Yes, it did all fit and it was easy to get the cover to close!

The GoWeld wasn't trying to be compact.   What they did provide however may be worth the extra space.

There was plenty of room in the bottom for some extra spools of wire, all required cables, accessories for welding with gas (such as the regulator) and plenty or room to spare.

Why all the extra room?   They made the case larger so you can place a few small battery's, such as motorcycle battery's, in the case with the GoWeld so you don't have to pull them out of a vehicle for a quick trail repair.

The top shelf of the case is form fitted to hold the GoWeld, a spare wire spool, plus an array of extra parts.
Setup for both of the units was similar, you hooked the battery's up in series, creating one 24 volt power source.   Both units came with all the necessary cables to do this.   The first thing that I noticed was the length of the cables between the battery's and the welders.   The Readywelder II had a very short cable, about 10 feet, while the GoWeld had a cable around 20 feet long.     The trigger on both controls the wire feed, but both of the units are hot as soon as you hook them up so you have to be careful about touching the tip to anything.   
We started by doing a series of welds with the GoWeld.   Tony made a number of lines and welded some pieces of scrap together.

We then did a series of welds with the Readywelder II.   After Tony had done some welding with both units, I decided to try my hand.

This was my first weld with the Readywelder II.  

Here you are looking at a picture of my first weld with the GoWeld.   On my very first weld, I was able to produce a weld that even surprised me!   It was a good solid weld that even looked pretty nice!

The GoWeld seemed to have much better power and I was able to produce a cleaner weld than with the Readywelder II.

So, when it came to the portable units there were a few different things that each individual will need to take into consideration.   Cost, size, features and performance are a few that came to mind right away.  Either way you go, you will have a welder that is more than capable of getting you home!

This is the price and warranty info on the two portable welders.

Readywelder II
685 (MSRP)
2 year parts and labor
1 year
* I was unable to find an MSRP, so I searched and averaged the prices I found on the internet.


Because we wanted to keep things equal during the tests between the Mobi-Arc, Zena and Premier Power Welders, we always used the same welding rod, 4/32 or 1/8.   While this did make things fair for the tests, in a way it was also not correct.   While all of the welders were able to weld with this rod, we felt that depending on the machine and skills of the operator that the rod selection could be tuned to suit ones individuals needs.    It was recommended to us that a good rod for the novice welder would be 3/32 rod.

So in the end, what does it all mean?  

For the vehicle installed units, all three clearly demonstrated that they were all good welders that were more than capable of performing not only trail repairs, but also day to day welding.   They each had some individual features, and you just need to compare the three and go with the one that fits all your needs and wants.

When it came to the portable units, it was felt that the GoWeld was the superior welder.   With its advanced features, low battery cutoff and metal chassis we all felt that it was well worth the extra cost.   


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