Is running 1600BTU MarinAire on battery/solar possible?

[KingGuppy]

Does anyone run a similar AC unit off of solar/battery, using a soft/easy start device?

MarinAire 16k BTU:
Max. input consumption: 1480 W
Running Current: 10.8 A
Strating Current: 17.6 A

We have around 1000w of Solar, and 1200ah of batteries.

Our invertor is a Magnum 3000:
Output Power 3,000W
Peak Watts 3,500W
Output Voltage 120 VAC
Output Current 25.0 amps

Our goal is to be able to run the AC a few hours during the day when the sun is out, and then an hour or two at night.

We plan to add another 300w solar, and change batteries to lithium, but we weren't sure if we need to upgrade the inverter as well. Or if this would be possible with that setup.

Thanks for the help.

[iSaint]

I've never read where it was possible. If you get it worked out patent it and let us know.

[KingGuppy]

Originally Posted by iSaint

I've never read where it was possible. If you get it worked out patent it and let us know.

We thought it may be possible with an EasyStart.
https://www.microair.net/products/ea...r-conditioners

Would the 10.8 be around 120ah at 120v, giving us a few hours each day from our 1200ah bank?

I don't know enough about electrical to know if this is how it works, or what a realistic expectation is.

[markcouz]

10.8A at 120V = 1.3kW.

Your 1000W PV can be expected to produce 4 to 5 kWh per day in the Caribbean.

I would expect the aircon described to consume all the energy produced by your PV setup in 3 to 4 hours of use (on a good PV day).

While battery capacity is important, energy generation to maintain the bank is equally important.

[Howard888]

See Emily and Clark's Adventure you tube vlog. They have done it with a soft start and lithium batteries.

[captstu]

I had a 16 kBtu per hour unit on my Voyage 43’ cat. The house panic was 1700 amp hours fed by to 200 amp alternator‘s, one in each engine, and to 250 W solar cells.

When entering in Anchorage I started the engines anyway and turned on the air conditioning to cool down the boat. We let the engines run at a high idle until bedtime and turn them off. By then the air conditioning was cycling to maintain temperature.

About 6:30 in the morning even the cycling ran the batteries down below the point where the Inverter would operate.

It is possible under solar with one caveat. In order to support the starting load, we ran four strands of double zero wire to the battery distribution and two strands for each pole from the battery distribution to the two banks. We ran in the both position I kept the alternator as close to distribution box as possible.

The setup destroyed several drive belts that were installed prior to the age of common tooth belts, the system otherwise worked without too much difficulty.

Once the unit was cool down and both engines running we could also operate our washer dryer combination.

One note, even with solar you will be tempted raise the capacity of your engine alternator because it will extend the air conditioning time. While even a modest increase in alternator size will extend the time that your solar can Operate the load, a large alternator would yield all night cool.

In our case the standard run time coupled with the increased heat destroyed both engines at about 5000 hours each, still cheaper and quieter running a generator but it cost nevertheless.

There is another solution.

When I traded boating for travel trailing, I removed the 16,000 BTU for our unit in the trailer and replace it with a mini split. A mini split draws about 500 W at steady state cooling and keeps the trailer comfortably cool in mid Florida sunshine. Has a side benefit for 510 W the mini split heats the trailer to a comfortable 75° when is in the low 30s outside. Since it draws roughly 1/3 power for about the same cooling as your present system, and doesn’t require water so it doesn’t clog up, a mini split would be a good solution if you can find a place for the condenser.

[skipmac]

Hi KingGuppy,

A question that comes up on the forum several times a year. The short answer is yes BUT comes down to a LOT of battery to run it more than an hour or so. The Marineair power use is pretty typical. Very roughly 10.8 amps at 120VAC will require 108 amps at 12VDC to the inverter.

Even if you assume only 50% duty cycle (will be closer to 100% during a cooldown phase in the boat) allowing inefficiencies in the conversions you'll be using at least 60-70 amp hours from the batteries every hour of use.

You don't mention but assuming you have lead acid batteries and not LiFePO then from full charge you will have around 600 amp hours maximum usable if you don't want to go below 50% SoC in the batteries. Depending on the other loads; lights, refrigeration, electronics etc you should be able to run the air conditioning for a few hours on battery.

Starting from less than full SoC reduce that accordingly.

[rwidman]

I doubt that your current inverter will run that AC unit.

Air conditioning can be run from a solar system, batteries and an inverter, but it will take more solar panels and batteries than you can practically mount on a boat. It's done in rural areas and mountain cabins and such, but unless you cover all the vertical surfaces of your boat with solar panels and fill the bilge with batteries, it's not going to work on your boat.

[skipmac]

Originally Posted by rwidman

I doubt that your current inverter will run that AC unit.

Air conditioning can be run from a solar system, batteries and an inverter, but it will take more solar panels and batteries than you can practically mount on a boat. It's done in rural areas and mountain cabins and such, but unless you cover all the vertical surfaces of your boat with solar panels and fill the bilge with batteries, it's not going to work on your boat.

Hi Ron,

I'm running my 16k BTU air con with a 2000 W inverter but had to install an EZStart to handle the initial inrush. After that it's fine.

OP sail he has 1200 ah of battery. Even assuming only 50% usable if a lead acid bank that's 600 ah available. Even if the air con ran 100% duty cycle at 10.8 amps and reserving 200 ah of the bank for other loads that would be four hours run time on a fully charged bank.

That could be long enough to cool down the cabins and drop the humidity for the night.

[skipmac]

Originally Posted by KingGuppy

We thought it may be possible with an EasyStart.
https://www.microair.net/products/ea...r-conditioners

Would the 10.8 be around 120ah at 120v, giving us a few hours each day from our 1200ah bank?

I don't know enough about electrical to know if this is how it works, or what a realistic expectation is.

Based on the system on my boat and running the numbers I would agree with your math.

FYI long ago in a galaxy far away I had a degree in EE and remember just enough to calculate amp hours and to convert power use from AC to DC and back.

[guyrj33]

What you’re suggesting is indeed possible. As many others have pointed out the more solar and the more batteries you have the better.

[KingGuppy]

Originally Posted by skipmac

Based on the system on my boat and running the numbers I would agree with your math.

FYI long ago in a galaxy far away I had a degree in EE and remember just enough to calculate amp hours and to convert power use from AC to DC and back.

Appreciate this skipmac. The batteries are lead acid. The plan is to upgrade, but we're doing research on the most cost-effective way on that.

How often are you running your AC often with that setup?

[wingssail]

Not something I've done (but I've tried running 8000BTU off of a 1000watt inverter, doesn't work) but I think the power available from your inverter should be able to drive the air con, once it is started. So EZ start or soft start would be needed.

Of course you'll need large and perfect wiring and components on the 12v side to supply that load continuously w/o overheating and/or voltage drops.

But the big issue, from my perspective, is daily requirement to supply 600-1000 amp hours back into the battery. Yes, with two engines and big alternators, you can do it with several hours of charging each day.

That will be a lot of engine time plus a lot of wear and tear on the alternators, engines, batteries, and other components.

And THAT means a lot of attention from you.

Basically you'll be turning your cruising yacht into a power station for your air conditioning and you become the power station engineer and operator. I frankly like nothing better than when the engines go silent, both while sailing and at anchor.

So our solution to beating the heat is to anchor where there is some breeze, have plenty of ventilation (including fans) and shade and to keep the air conditioner turned off unless we're at the dock.

[deKlerk]

In short, this has been tried in the trucking industry and has never had a positive outcome.

[KingGuppy]

Originally Posted by wingssail

Not something I've done (but I've tried running 8000BTU off of a 1000watt inverter, doesn't work) but I think the power available from your inverter should be able to drive the air con, once it is started. So EZ start or soft start would be needed.

Of course you'll need large and perfect wiring and components on the 12v side to supply that load continuously w/o overheating and/or voltage drops.

But the big issue, from my perspective, is daily requirement to supply 600-1000 amp hours back into the battery. Yes, with two engines and big alternators, you can do it with several hours of charging each day.

That will be a lot of engine time plus a lot of wear and tear on the alternators, engines, batteries, and other components.

And THAT means a lot of attention from you.

Basically you'll be turning your cruising yacht into a power station for your air conditioning and you become the power station engineer and operator. I frankly like nothing better than when the engines go silent, both while sailing and at anchor.

So our solution to beating the heat is to anchor where there is some breeze, have plenty of ventilation (including fans) and shade and to keep the air conditioner turned off unless we're at the dock.

Yeah, that would be a lot of engine running.

We had planned to add more solar, to eventually get to around 1400watts. With the AC mostly being run when the sun is out and its hottest, it may not be a complete drain.

Definitely don't want to rely on engines daily for it. What do you think I would need solar wise to make it possible?