12 Volt Inflators

[Captain Smollett]

Anybody have a clue how much current these little 1.1 psi inflators draw?  Ones like this:



I'm thinking about getting this "nicer" one for the additional features it has, but it draws 9.9 amps.  About the biggest thing against it in my mind right now is having to cut the clips off and install an accessory plug (not a big deal, but I resist cutting up brand new stuff).  At $90, it's a bit pricey, though, too.



It has an adjustable automatic cut-off up to 4.4 psi, so I could set it to the max tube pressure on my dink. I'd still have to manually top off the floor and keel, but that's no biggie.

[CapnK]

If you can get a big-bodied manual pump of some sort, that's the way to go in my experience. The little electric pumps I've had/seen/tried seemed to pump more noise and current than anything else.

Did you dink come with one of the foot bellows? The one I had on the inflatable WM dink worked great.

[AdriftAtSea]

The other problem is that most inflatable boats don't require or recommend a powered pump, as they require very little air pressure.  Over-inflating them is an easy way to really damage them.

I'd second the idea of a foot bellows pump.  It's quieter, smaller, easier to store, more reliable and doesn't require electricity.

[Captain Smollett]

I HAVE a foot pump, and a manual cylinder pump.

I have not tried the foot pump with the new dink yet because I have to get an adaptor for the valves.  So, I don't know how long it takes to pump it up with that.  The old dingy took 5-7 minutes with the foot pump if I pumped on it fast, and the new boat is definitely bigger.

With the el cheapo, came-with-the-boat cylinder pump, it takes 20+ minutes to pump up the new dingy.  Well, it did.  There's something wrong with the pump, and the other day it took over 35 minutes, and that was with Becky and I taking turns so we could maintain a rapid pumping rate.  A GOOD cylinder pump is about as expensive as cheaper 12 V (some of those run $200+).  I really don't like pumping with these, however, since I have to bend over too much and it hurts my back.  On this, the foot pump wins HANDS DOWN (no pun intended).   :)

As for pressures, I already checked that. The first pump I showed will NOT achieve the recommended pressures for ANY of the chambers on my boat; it only outputs 1.1 psi.  The second one is adjustable to deliver the pressure you want.  Only the 3 main chambers are below the maximum output of the pump, but since I can SET THE OUTPUT of the pump, that SHOULD NOT be an issue.

The second pump showed, the 'better' one, came off a web site largely catering to big, commercial rafting organizations.  That is, they pump a large number of boats in short period of time; it's also the the site recommended by my boat's retailer (that's why I took a look).

I got interested in looking at 12 V inflators when someone on THIS site said they use one (Fortis I think) and liked it.  5 Minute total pump-up, and that's with a low pressure inflator that required manual top-off to get full pressure in the tubes.  While we were pumping the other day, the SP employee came over to chat.  After he had seen us pumping for what seemed like eternity, he commented "I got a cheap inflator from Wal-Mart and it takes about 2-3 minutes to pump up a boat."  Comments like these made me curious to look at them.

Keep in mind that this will be used for weekend "car-boating" with the power source being the car battery (with alternator) as well as being the dingy on the big boat.  In that scenario, a little convenience goes a long way.

If it really only takes a few minutes (say five or less), I can live with the 9.9 amps of the nicer model; but I SURE don't want to spend $$ on the cheaper ones (still nearly $50) if they draw nearly as much current.

[AdriftAtSea]

What kind of dinghy is the new boat??? If you said, it might help with finding an adapter for the foot-bellows pump. :)

[Captain Smollett]

What kind of dinghy is the new boat??? If you said, it might help with finding an adapter for the foot-bellows pump. :)

I don't need help finding an adaptor for the new boat.  It's not that big of a deal to find one; many web sites sell them.

I want to know if anyone knows how much current the cheaper, low pressure inflators draw.  But it may be moot.  I'm nearly sold on getting the bigger one if I get any at all.

[Captain Smollett]

The other problem is that most inflatable boats don't require or recommend a powered pump, as they require very little air pressure.  Over-inflating them is an easy way to really damage them.

Oh yeah, I forgot this earlier.  My inflatable has relief valves in the main chambers to prevent overinflation.

The floor and keel chambers are pretty high pressure; with a manual pump, the pump hose-to-valve fitting leaks before these get too high.

It's really a well engineered boat.

[AllAboutMe]

I almost hate to ask, but why does current draw matter? If you're using your automobile battery as the source, it won't put any significant strain on the battery. And, if you're using the boat battery, you'll be motoring out AFTER having inflated the dinghy...right? Recharging the battery? And if it's really a problem, buy a 110 volt rechargeable.
Also, why not leave the alligator clips? Having a plug is nice, but is your battery that inaccessible? Just playing devil's advocate....
Larry

[CharlieJ]

I think the point here is inflating the dinghy while out at an anchorage, OR inflating it after you have come in from a passage and are anchored up somewhere- far away from the car battery. And likely won't be motoring anywhere for a while.

Most of us have in the past cruised for a bit, or are planning to do so and much of this is slanted towards NOT being where things are that available.

And don't "hate to ask" We've found out some very interesting things in the past when a question like yours led to very good answers.

[Captain Smollett]

I almost hate to ask, but why does current draw matter? If you're using your automobile battery as the source, it won't put any significant strain on the battery.

You are right...current draw is not an issue for the car-boating situation.  But that scenario is only a driving force in wanting to get an inflator/deflator - less time (and less work) at the ramp.  If I spend money on a piece of gear, I really don't want it to be single use..ONLY for car-boating.  If practical, I'd like to include it on the cruising boat.

And, if you're using the boat battery, you'll be motoring out AFTER having inflated the dinghy...right? Recharging the battery?

Charlie really hit this one, partly.  For sailing protected waters, I don't mind towing the dink. But outside, I prefer to stow it than to tow it.  When I arrive at an achorage, I'm generally pretty tired, yet one of the first things I need to do is inflate the dingy.  An inflator, if suitable for me amp budget, would be a nice luxury.

And I might be on the hook for a while, so I'm definitely NOT motoring out right after inflating.

Further, you have to keep in mind that my boat is equipped with an outboard - the charger is not a high output marine alternator, it is 5 A.  As such, I don't even factor it into my energy budget calculations.  In other words, for the sake of this discussion, let's pretent that I don't have an engine for onboard charging.

And if it's really a problem, buy a 110 volt rechargeable.

Not suitable.  I'll need to recharge it sometime, and 110 V likely won't be available.

Also, why not leave the alligator clips? Having a plug is nice, but is your battery that inaccessible?

Thought about it, but yes, the battery bank really is rather inconvenient.  The bank is stored in the engine compartment, where the A4 used to be, behind the companionway steps.  Not impossible to get some clips to, but I'd have to climb down, open the steps, clip on, then climb OUT without the steps (or rig some lead arrangement), inflate, then go below all over again.

As it is now, I have an accessory plug just inside the companionway.  It would be a dirt simple matter to plug it in there.  No in-and-out, not fiddling with getting to the batts.  Remember, if I buy it all, it is to increase convenience, not be something I have to work to use.  Before I did all that, I'd just assume use the energy to manually pump up the boat (which I have done in the past and really have not complained about it).

Just playing devil's advocate....

Always a good thing.   ;)

[Auspicious]

I recognize your comment about the limited charging from the outboard alternator, but I (who is not you <grin>) would tend to leave the outboard running while inflating. I think practically speaking, most of the time you will be motoring either shortly before or shortly after wanting to inflate the dinghy.

Since your outboard charges the batteries when it is running (as minor a factor as it is), can you reach power conveniently at the outboard for the alligator clips?

Perhaps you could put a connector in the power cords so you can swap between the accessory plug and the alligator clips.

Not applicable to you, but something I'm thinking about that might be interesting for people with inboards: the off-road truck guys often carry onboard air compressors. There are expensive 12V compressors that some use, but it turns out that there are some air conditioning compressors (Volvo I think) that are internally lubricated, so they don't need a refrigerant for lubrication. People mount the a/c compressor as an air compressor; the electrical clutch works nicely so you don't waste power driving the compressor when you aren't using air.

The appeal to me includes size -- the installation takes much less space than a pancake compressor.

I'm still working all this out in my head -- it is part of a concept to carry a TIG welder on board (I have 240V as well as 117V from my generator) and it would be nice to have air for grinders and drills (yes, I could use electric but I already *have* all those lovely pneumatic tools).

Sorry for the hijack Charlie -- back to 12V inflators now. <grin>

sail fast, dave

[Captain Smollett]

I recognize your comment about the limited charging from the outboard alternator, but I (who is not you <grin>) would tend to leave the outboard running while inflating. I think practically speaking, most of the time you will be motoring either shortly before or shortly after wanting to inflate the dinghy.

Assuming the outboard was even running to begin with, that's okay.  I HAVE been known to anchor under sail.   ;)

Beyond that, and it's just a habit I would have to change, I tend to kill the noisy beast as soon as humanly possible.  Leaving it running to pump up the dink would only require a mental shift.

Since your outboard charges the batteries when it is running (as minor a factor as it is), can you reach power conveniently at the outboard for the alligator clips?

Hmmm.  I'm not sure how other outboard chargers are rigged, but mine is simply two leads that come off the electronic ignition module.  Convenience is a relative term, but I don't see taking the engine cover off (a PIA in itself the way the outboard is mounted on the Alberg) and clipping to two little butts of the eye connectors that if memory serves are painted over anyway as being something I'd want to do as a matter of course.

But perhaps you meant something else?

Finally, as an added complication/consideration, the outboard on my little boat does not have a charger.  But in this case, getting the clips to the battery would be more convenient than on the big boat (a plug still moreso, however).

Perhaps you could put a connector in the power cords so you can swap between the accessory plug and the alligator clips.

That's a really good idea.  I like building versatility into the system.

The other thing I guess I did not mention that makes me favor the accessory plug idea is that the Durango has an accessory socket in the rear compartment, just internal of the tail gate.  So, the acc. plug would be convenient for the car-boating option as well, rather than going to the truck's battery with the clips.

Just some thoughts....

Thanks for all the input, guys.  Who knew the "simple" process of inflating a dingy could spark so much discussion...   ;D

[sailor]

I want to know if anyone knows how much current the cheaper, low pressure inflators draw. 
But it may be moot.  I'm nearly sold on getting the bigger one if I get any at all.

I have an el-cheapo inflator, similar looking to the one you posted.
About 4 Amps in free air, almost 7 Amps when I completely cover the outlet.
Of course YMMV.
Why not buy both, measure both Amps draw and time to inflate and return the one you are not happy with?

[Captain Smollett]

Okay, found some more info on the "nicer" unit that talked me out of it.  It is very, very slow (low volume pump), and is prone to overheating and diaphram failures.

[AdriftAtSea]

And that's the more expensive, nicer unit... UGH... give me a foot pump any day.. :)

Okay, found some more info on the "nicer" unit that talked me out of it.  It is very, very slow (low volume pump), and is prone to overheating and diaphram failures.

[Fortis]

We use the same pump as pictured to inflate the retrieval stretcher on board the coast guard boat...I think it is hugely over-rated and over priced. I have a 12v power inflator for my dinghy which I think works considerably better. It is just an impellor/fan pump, but it does the job. Inflates the big dinghy in under two minutes, leaving just a few strokes with the hand pump to get it up to correct stiffness if you care to bother.

It does not drain much power.

What it comes down to is that you have a choice of pressure or volume. High volume pumps cannot by their nature manage much pressure, and high pressure pumps need to be huge in order to manage a reasonable volume.

I opt for the highest amount of volume I can practically get, and then have a high pressure hand pump to finish off.

Alex.

[Captain Smollett]

Thanks, Alex.  I was hoping you'd chime in here, since I thought it was you who mentioned using an inflator aboard.

I've ordered the a low pressure pump (not the one shown above, but similar).  I like the idea of inflating in two minutes when car-boating (or even aboard).  My dingy is a 9 footer that takes just over 20 minutes with the hand-pump supplied by the retailer.  I'll test it soon with the foot pump, as soon as the adaptors that I finally got around to ordering arrive.

2 minutes at 4.5 amps is 150 milliamp-hours.  I think I can afford that aboard, for the convenience of getting the dink ready in 2 minutes vs. 20.

[Fortis]

I will post pics of the two pumps I use, and th eone that I used to use, which still has some advantages, but just finally died of old age) when I am not so tired I can see straight.

Dodged almost continues rainstorms and lumpy seas that reached all the way intot he marina in order to bolt on 4 deck organisers, two triple clutches and a bunch of clam cleats and fairleads....I think the boat will end up having about 6kg of just small stainless bolts holding the deck hardware down...can't believe how many we put down today...and tomorrow is when the headsail tracks go down, that's another 48 of the little buggers!

Thank god it is not a cored deck or cabin....I would be there till retirement!


Alex.

[Captain Smollett]

Finally got around to testing the electric inflator:

Hand pump that came with the boat: 35 minutes

Foot Pump that I used with the old dingy: 12 minutes

12 V inflator: 8 minutes