Adding an Inverter

[ericinmich]

Plenty of boats have invertors on them. Just use a marine rated one, sized right and with correct cabling.

Just looked it up, at 900 watts, that is a lot, but an invertor direct wired to the battery and running it while the engine is running will work fine.

As far as the electrical shock hazard around water, AC vs DC doesn't matter, both can be deadly. Since both in a boat running off battery are limited by the power source the problems are the same. The issue around water with AC is due to dock/shore power which is an "infinite" source.

[IDBoating]

As far as the electrical shock hazard around water, AC vs DC doesn't matter, both can be deadly.

True, but generally the DC in this context is around 12V while the AC is around 120V (!!!). That makes a big difference.

Since both in a boat running off battery are limited by the power source the problems are the same. The issue around water with AC is due to dock/shore power which is an "infinite" source.

If he installs an inverter capable of 10+ amps at 120VAC, that's close enough to "infinite" to kill someone. Most shore power is going to be fused/breakered to 15-20A per circuit. If his inverter can supply 10A, it won't matter that shore power can provide an extra 5-10 amps... he'll already be gone.

[BlackoutATX]

True, but generally the DC in this context is around 12V while the AC is around 120V (!!!). That makes a big difference.


If he installs an inverter capable of 10+ amps at 120VAC, that's close enough to "infinite" to kill someone. Most shore power is going to be fused/breakered to 15-20A per circuit. If his inverter can supply 10A, it won't matter that shore power can provide an extra 5-10 amps... he'll already be gone.

Well I'm not doing it lol. I don't need it for anything other than a pump. So it's just not worth it. If I had other needs though I wouldn't hesitate to tackle this.

[UNSTUCK]

Well I'm not doing it lol. I don't need it for anything other than a pump. So it's just not worth it. If I had other needs though I wouldn't hesitate to tackle this.

Just a bump? Don't sell yourself short. It may have started as just a pump. But then you would have realized all the possibilities and before long you would have had the blender going full speed all day long!

[IDBoating]

And a blender wouldn't draw nearly as much current - and thus not require as big an inverter - as his big ol' pump.

So it's decided: No on the pump, yes on the blender!

[BlackoutATX]

A blender would be nice! Well I got the AIRHEAD AHP-12HP High Pressure Air Pump 12 Volt today and took it out to blow up the same island. This thing sucks. It's literally terrible. My little bitty obrian 12v pump does a better job. So I'm either going to try and find a better 12v pump, or proceed with adding an inverter.

[IDBoating]

Visit NRSweb.com and look at their 12VDC pumps. They are a whitewater supply house in my region, and it takes a serious pump to inflate big Hypalon rafts. They are awesome to work with and great with phone questions.

[BlackoutATX]

Visit NRSweb.com and look at their 12VDC pumps. They are a whitewater supply house in my region, and it takes a serious pump to inflate big Hypalon rafts. They are awesome to work with and great with phone questions.

Thats funny, I was actually just looking at the Bravo pump on their website.

Edit: By the way, if anyone is interested in the Bravo pump, its on sale at Austin Kayak Company right now. Also, if you sign up for their email list you will get a 15% off one item coupon once a month. They are a great company and one of the only places I know of that will let you use a coupon on Yeti products.

[BlackoutATX]

Well I received the Bravo Pump today. While it is the best 12v pump I've tried, it was still disappointing. The same island I've been testing all these on took 22 minutes with the Bravo. With the 120 Super Pump, 5 minutes. Considering the Bravo was $146, it will be going back.

The LVM pump from NRS has my interest. But it appears to have a lot of failure problems. ( http://www.nrs.com/product/1707/lvm-inflator-pump ). I might give it a shot for the hell of it. But at this point I'm leaning to the inverter again. Besides, I'm now craving margaritas on the boat.

[chpthril]

So why did you abandon the 12V DC to 120V AC converter?

[BlackoutATX]

So why did you abandon the 12V DC to 120V AC converter?

Really just for simplicity. If I could have found a 12V pump that satisfied me, I would just go with that. But now I'm thinking thats not going to happen. I'm thinking about mimicking my setup I have in the port rear locker for my Pro Mariner. I could mount it on the back of the starboard rear locker compartment. Then using a Blue Sea switch (which I already have) and an outlet version of this port plug, ( http://www.amazon.com/NOCO-Genius-GC...ilpage_o01_s00 ) I could keep everything contained and hopefully dry. Step 1 is finding an inverter I feel can hold up on the boat.

[chpthril]

The new Malibu m235 has a built in 115v inverter
You can see here all the power and switches are available in the forward walk through. [ATTACH]42931[/ATTACH]

not really built in but mounted to the boat just like an amp or a battery charger, but rather with a useless AC receptacle that mounted behind a door thats too shallow to close while in use. This leaves a swinging door flopping around while on the water.
Also, the 12V socket is not deep enough to plug anything in to. Door stays open flopping around

[chpthril]

Really just for simplicity. If I could have found a 12V pump that satisfied me, I would just go with that. But now I'm thinking thats not going to happen. I'm thinking about mimicking my setup I have in the port rear locker for my Pro Mariner. I could mount it on the back of the starboard rear locker compartment. Then using a Blue Sea switch (which I already have) and an outlet version of this port plug, ( http://www.amazon.com/NOCO-Genius-GC...ilpage_o01_s00 ) I could keep everything contained and hopefully dry. Step 1 is finding an inverter I feel can hold up on the boat.

Ok, so look for a marine 12V to 110DC inverter that meets your demand + 25%. This gives you a little cushion so the inverter is not working full tilt when in use.

[IDBoating]

If you're going to run a 120VAC motor (i.e. a pump), the usual rule of thumb is at least 50% overcapacity due to inrush current at motor startup (100%, or 2X rated current, is better). A motor at startup with a motionless shaft has zero CEMF and thus represents almost a dead short until the shaft starts turning and CEMF starts limiting current. That's a hard load for an inverter, and could either annoyingly pop its breaker all the time or damage its pass transistors over time.

It's really a question of wattage. If you want AC blower performance from a DC blower, the latter will be just as large as the former but (at 12VDC) require roughly 10X the current. You like the speed of that 900 watt AC blower? You'll need a 900W DC blower to duplicate it, which in a 12V environment will be (900W / 12V =) 75 amps DC continuous. Ohm's Law and the Laws of Thermodynamics are absolute, you really can't get something for nothing... if you cut the voltage to 1/10th you must increase the current by 10X to compensate. And putting an inverter in the loop doesn't change that, because it's still 900W input to get 900W output (actually a bit worse due to <100% efficiency).