Viar 12V compressors - off the trailers batteries?

[afk314]

I'm considering purchasing a 12v Viar inflator (maybe a 450p-rv) but keep reading that I'll need to use my tv battery while the engine is on. That's kinda a pain for me. I understand that a single 12v battery won't have the amps, but I'm curious if attach to the trailers battery system if the two batteries together can meet the needs without being sufficiently drained.

Or is the problem that the batteries aren't "fast" enough to provide the startup amp?

-Adam

[Rivet Rocket]

I have a Viar compressor and it works great to inflate to 65 PSI for my needs. I use it as instructed in the manual. Draws a lot of juice and my TV revs when in use. With no alternator you will drain the RV batteries quickly. The power cord and compressor line are long and reaches my tires with ease. It gets hot and has a limited run cycle before it needs to be shut down to cool off.

Not sure why you do not want to use the TV, but my guess is the 2 batteries only will not meet your needs, drain down before you complete airing 4 tires.

Others may chime in with their experiences, but sometimes following instructions is the best route.

[afk314]

Thanks!

So, given the included electrical cable and hose length you are able to top off the tipes while hitched up? That'd be fine for me, I just didn't want to mess with extensions if I didn't have to.

Thanks,
Adam

[Rivet Rocket]

Sorry, may have given you the wrong impression. I run the compressor with the TV uncoupled from the trailer. Have the hood of the TV facing the tongue of the trailer. Don't think the wires are long enough to reach both of your axels if you are hooked up. If you approach it from the other direction (hood facing the rear of the trailer up close you should be OK). Hope this adds some clarity.

[Piggy Bank]

We have the 88P Viair and think it works great.
We can use it to top off the air by just attaching to the tow vehicle battery. The vehicle does not have to be running.

Is there some reason that this is not a good idea? Seems to be working fine.

[majorairhead]

I have a viair 88p.

I topped off 4 tires on my craftsman lawn tractor, 6 tires on my grasshopper zrt, 4 tires on my f150, 4 tires on bicycles, and a wheelbarrow tire, all in one session, all by having the viair hooked up to the battery on the grasshopper, without the grasshopper running, and had no problems whatsoever.

[STREMN]

I use the 450p with a portable jump pack. Saves the need to hook up to the TV or tie into the trailer system.

The jump pack easily provides the power to run the Viair Compressor. It's an extra piece to carry but it's a source for 12v power as desired.

Tom

[SteveSueMac]

Bob Cross gave me a great tip to attach a 7-pin connector so I could plug my Viair in to my truck's 7-pin plug to run the compressor off my truck's batteries - which I do without turning the truck on. I can top off all 4 tires if needed without any real strain on my truck's batteries.

[Ted S.]

I run the Vair 450p RV off my Airstream batteries all the time with no issues. In fact I set it up with a quick disconnect from the trailer batteries.

[AirstreamCSH]

I do the same as Ted. No problems.

[OTRA15]

Lots of variables not being considered thoroughly IMO.

Is shore power connected? How many tires are being filled, or is the trailer perhaps being winterized on the road?

The strictly correct way is to use the tow vehicle's single battery while the engine is running. Multiple batteries in TV and AS introduce other variables.

More variables means more risk.

Deviation from normal procedure introduces more risk.

If using the AS batteries, monitor battery voltage on the panel (after loads are removed).

If your tow vehicle's engine won't start because of a discharged battery, you went too far and will have to turn around!



PS a longer air hose extension is one option.

[Excella1991]

Originally Posted by afk314

I'm considering purchasing a 12v Viar inflator (maybe a 450p-rv) but keep reading that I'll need to use my tv battery while the engine is on. That's kinda a pain for me. I understand that a single 12v battery won't have the amps, but I'm curious if attach to the trailers battery system if the two batteries together can meet the needs without being sufficiently drained.

Or is the problem that the batteries aren't "fast" enough to provide the startup amp?

-Adam

I have a Slime tire inflator. It runs on 12v or 120v and has a rechargeable battery. It's small and lightweight. No long hoses. Just carry it from tire to tire. I bought it specifically to use with my AirSafe hitch. But now I use it for everything.

[Pongo]

I've the 450P-RV unit:
[LIST][*]Quality is excellent. The kit is very comprehensive with all the attachments you will ever need for the coach, the spare, and other applications.[*]The 2 air hoses will easily reach from your TV to the end of a 33' trailer[*]Per the manufacturer, use of a 7-pin jumper will void warrenty. The issue is current draw, which is why the unit comes with battery terminal clamps in lieu of lower current draw connectors, e.g., cigarette charger plug.

[Mollysdad]

Watch:

https://www.youtube.com/watch?v=Yzv3ymNZ5zQ&t=194s

[AStreamNerds]

I have always just opened the battery box on the trailer and connected the battery clamps to one of the two batteries to air up my tires. When having the solar upgrade done and the batteries being moved inside Lew put a set of terminals on the side of the battery box for me to use instead. No issues at all. When connecting to my truck when airing up for the sand I use the truck battery but keep the truck running out of habit.

[Troutboy]

I use the Viair 450P off my airstream batteries, 320 Amp-hour of lithium. Works great. I made a custom remote battery terminal to hook the Viair and a Flojet macerator pump up to. Does not drain the batteries at all.

[Adiredneck]

I always have used my Viair powered off the truck batteries, while idling. I use it to top off the four truck tires, four trailer tires, and AirSafe hitch. Since a Ram club-cab 3500 with 8' box and 27 FB Classic make for a very long rig, I decided to go a different route. I bought a 6' Goodyear air hose with quick connects, a good Milton chuck with built-in gauge, and a Jegs 5 gallon air tank, (http://www.jegs.com/p/JEGS-Performan...27491/10002/-1) which I modified by adding a shut-off vale and female disconnect. Since the Viair has a male quick-connect, I can fill the tank with 100 lbs of air, and then take the air tank, hose and chuck to whichever tire I'm filling. Takes a couple refills on the tank, but still easier than dragging hose and wires back and forth for 40 feet. Added bonus is that all of the above is made in USA!

[lsbrodsky]

I made a cord for my VIAIR using a 7-way connector, which I plug into the truck with the engine running. In the hitched position, the air hose easily reaches all truck and trailer tires.

Larry

[pcskier]

Originally Posted by afk314

but keep reading that I'll need to use my tv battery while the engine is on. That's kinda a pain for me.

It depends. For example the Viair 450p manual does not state anywhere that the engine needs to be running. For longer trailer/TV combos, that's the ticket, and also the hose provided is longer at 30 feet. The 88p (which I have for my 23') states in the instruction manual, at least twice: IMPORTANT: Engine MUST be running while using this compressor.

I don't know why. I checked with Viair to confirm, and they repeated that. So their engineers have their reasons, which is good enough for me...fortunately I can reach my tires (just barely) hooking to my TV battery. If not, I could see the temptation to run of the trailer batts when hitched up.

So, shop carefully and get what works for you. The technical info is all out there, Viair's site has the manuals for all their models. Proper checking of tire inflation is important enough on a daily basis (and I'm willing to bet that a majority of Rv owners check once a year only, or just once per trip) that having a compressor that is easy to use in your particular situation is critical. If it's a pain or inconvenient, it's less likely to be done. It should be part of the daily departure ritual. There would surely be less threads about failure of 'crappy' tires if more folks paid better attention to this.

[Carmen214]

I permanently mounted an onboard ViAir system with 2 gallon receiver on my TV. I have a quick connect mounted at the receiver hitch and use it for the Airstream, TV, motorcycles, etc. It's a bit of trouble to go through with the install but it's one less loose item to carry around.

The compressor will run without the engine running but it brings up the pressure faster with it running. It has an automatic pressure switch but I still have an on/off switch so it won't run unless I want it to.