12v AIR Compressor -What is good

My Pacbrake came with a 150 psi 12V compressor that sits right next to the passenger side battery. I have 1.5 gal of air storage on board, runs the Kline Air Horns well also.

I just retested mine as I had it, and my dc clamp on Meter out anyway.

When first turning and little resistance, 15 psi, it draws 19.27amps when battery voltage was 12.35.

By the time it got my suspension airbag to 100 psi,about 25 seconds later, it was drawing 15.47 amps.
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0.18 amps of that is the additional 80MM fan I attached to blow over the head

I expected the opposite. Higher amp draw at higher psi. Motor actually speeds up at higher PSI as amps drop.

My wiring run is a bit longer with about 10 more feet of 10 awg added where I snipped off the alligator clamps.

2nd test,

I just pushed the other airbag to 100 psi from 15psi. It briefly read 37 amps right after flipping the switch, but then then settled to 19.27a. It then slowly rose to 19.8a, and about the 45PSI level, amps began dropping, at 100PSI, 15.27 amps.

jrnymn7 wrote:

JiminDenver wrote:
We have been using this one for a while now. Faster than any I've had before. Will inflate a truck tire in 3 minutes.

clicky

Any idea what the input current (amp draw) is? I've read 30a in specs but LY says 16? thanks!

Honestly I have no idea. This is the MV50 spoken about in the rest of the post, just at local prices.

The wire from Unit to alligator clamps is 12 awg which is rated for 30 amps.

The fuse is 30 amps.

The draw varies between 16 and 18.5 amps when running.

Another thing to note, if airing up something already 75 psi, turn on the unit, then attach the schrader valve.

Do make sure to open up the air filter intake holes when it arrives, retorque the head bolts after the first heat cycle. Try not to get frustrated threading the schrader valve attachment.

The air filter makes it much quieter too. Never run it without it attached.

JiminDenver wrote:
We have been using this one for a while now. Faster than any I've had before. Will inflate a truck tire in 3 minutes.

clicky

Any idea what the input current (amp draw) is? I've read 30a in specs but LY says 16? thanks!

You should be fine with the MV50. A google search will turn up tons of posts, many on Jeep forums and most are satisfied. Depending on intended use, it looks like a good value.

Thanks everyone for your suggestions.
I just ordered the MV50 from Amazon.
I was going to order the Viar, but the particular model that I want/need is almost twice the cost of the MV50 which has the same specs.
You all have been a great help

Jack L

I've gotten a fair amount of use from my Mv-50 over the last 7+ years. I pump up my tires from 32 to 50psi, and my suspension helper spring airbags from 5 to 100psi. I also use it to prime my water pump, and I've reluctantly lent it out to people Whom could break an Anvil.

I gave it a tune up a few years back and tapped the head for 1/4 NPT threads so I could use better fittings.




It has some metric head fitting. There are adaptors. The part which slowly screws onto the Schrader valve is highly annoying.



Never run it with the air filter off.





Remove all the plastic mold flashing from the air filters intake holes . Huge difference.

They are easy to take apart, clean and fine tune as they were not assembled with love.

I attached a 80MM 12v fan to the handle which comes on with the motor.


They do get real hot, the cylinder head, not so much the motor, but especially when the cylinder is dirty. A little high temp grease between the cylinder's exterior and the heatsink goes a long way toward heat dissipation.



I cleaned and lubed the rubber piston cup with Syl-glide.

If you get one, find the right size allen wrench and retorque the head bolts. When I went to take mine apart, I found them finger tight.

These say max of 13.5 volts. I think a lot of failures one reads about in reviews are have been induced to overvoltage and overtemperature. The air filter is a big one. I found half the filter intake openings were occluded.

But also the 12v wires leading into it are not spliced very well and there was NO strain relief, so too much strain on the power cord and it can pull a wire connector off of the relay, or switch, or pull from the crimp connector.




Mine pulls 16 to 18 amps at 12.6v.

Do note that the stock air valve is passive. When the unit is turned on unattached to a schrader valve, air escapes the end oh the hose. If one modifies for better fittings, the new air hose can build pressure quickly and exceed 150PSI and something will break.

I drilled a hole through mine so it cannot self destruct. This locking chuck is key.



The yellow airhose is a harbor freight special. I've since replaced it with a much better quality hose of smaller coil diameter that is an absolute joy o work with compared to the HF or the original yellow Hose. I'm not using any quick release fittings, but I keep them handy just in case.


So the MV-50 can be turned into a capable machine, but it leaves the factory in serious want of some fine tuning.

Just a suggestion - nothing more
BEWARE of the compressors that are NOT rated at 100% duty Cycle
The link above is NOT 100% DC - Do your homework and understand your needs
For me if it's not 100% DC it does NOT fit my needs

I have one by ExtremeAire. I believe it's made in Australia, but sold US. I've been using it almost weekly on my Jeep for over 10 years and still works like new. Much higher flow than Viair, but costs more, too. Has a 100% duty cycle, so you can run it continuously all day.