Portable generator setup with aircon and inverter

[Julius1977]

Hi all, first time boat owner so hope I will find the same pleasure as any other boaters here. I own a 42 feet 2016 Prestige Flybridge. Nice boat for cruising in Mediterrenean waters.



So the boat has a little bit of a basic setup with not too many batteries, no inverter and some other features are missing. It has a 28000 btu dometic airconditioning system.


I was planning to do overnighters with it and also planning to install a genset to be able to run AC and with that aircon while on the hook. But it is a very big projects because engines needed to be taken out.



So I lowered my expectations. But rethinking all this, for the few times I need AC without shorepower, maybe better to buy a portabel generator inverter (2200 watts Honda or so), run it for a few hours in the evening to charge batteries and run aircon. I am aware of the dangers with the water/petrol and such and won't run it while sleeping.


-The dometic aircon has three units (two cabins, one saloon). Does that mean you also split the power needed when you run one or two units?


-Would a 2200 watt generator be enought to get the compressor going?


-If you have an inverter and a couple of good batteries, does that mean the generator adds up on the inverter power? (so you can do 2200 watts generator and add 2000 watts inverter from the power banks). Because start up phase take the big load at one?


-Does the 2200 watt generator power up the batteries quick?


-Any other suggestions?


Tnx in advance!

[Bill Seal]

believe almost all portable generators only provide 100W (8 AMPS) of power at 12VDC, so you would have to use some sort of ac to dc charger.

[smac999]

some inverters like the victron can boost to increase ac power. but then you are draining the batteries as you run the gen and AC

with the 2200 watt gen and AC you probably won't be doing any charging. all the power will be used. when you shut the AC off then the inverter /charger can start charging again. so you may need to run the gen for a couple hours for the ac and then a couple more to charge the batteries

you might only be able to run 1 or two of the ac units off the gen. but I don't deal much with AC. not needed up here...

[fxykty]

Originally Posted by Bill Seal

believe almost all portable generators only provide 100W (8 AMPS) of power at 12VDC, so you would have to use some sort of ac to dc charger.

Not necessarily true. We have a 2200W petrol generator (not a Honda, but a heap less cost) and it has its own inverter that spits out AC power. For continuous charging it maxes out at about 1900W (about 8A at 230V and 120A at 13.4V).

We run ours into our shore power inlet that goes to a Victron Energy Quattro. This is a combined charger and inverter. If there is any AC load that is less than the generator output then the charging continues but at a reduced rate while the pass through goes to the AC load. Once the AC load exceeds the output of the generator then the Quattro switches to inverter mode with all the generator output going to the AC load, plus some amount of inverting from the batteries.

But, and it may be because our petrol generator is a cheap model, it doesn’t like AC loads at all and simply reduces its output to match the pass through AC load (and stops charging). If the AC load goes above the generator’s output the generator quits and all the load is fed by the inverter.

This petrol generator is a temporary solution, so we haven’t bothered to figure out if it is a generator problem or something weird about our Quattro setup. It is WLL seems weird to me why the Quattro doesn’t just suck in all the power that the generator can give, regardless of charging, pass through or inverting. We do set the maximum input current for shore power to 8.0A when we plan to use the petrol generator.

[Rumrace]

The little Honda will run a microwave that’s it. Air on a boat on anchor costs $30,000.00 here period the end. $20,000 for the Onan and $10,000 for air It’s near the bottom of just about every option list identical price. I image it’s a lot more expensive to fit all the plumbing and mounting after the boat is built. The new Onan is in a suitcase kinda. The older ones you need skinny folks to crawl in and take apart bulkheads to get near them
Many moons ago and a few boats ago I put a bilge pump in the bottom of an Ice chest. I made a two hose plug for the drain. Built a box with two computer fans and a heater core from a Chevy. The box fit in the aft cabin window and ran on a solar panel with a small 20amp battery and charger.
So it doesn’t deal with humidity but cools a 35’ boat down fine. You can do the same thing tossing a pump and hoses overboard too. Low budget Air
Portable gens are dangerous on boat I feel. Many small power boat in the locks would toss one out on the lawn was safe but noisy. They all had different brands none of them running air or could.

[Chotu]

You can run ONE of those air conditioners with a little suitcase generator if you’re lucky.

But you’ll need to get a soft start installed in the air conditioner to allow you to more easily handle the locked rotor. This ensures you can definitely run it from a little suitcase generator.

https://www.microair.net/collections...RoChMEQAvD_BwE

[GordMay]

Greetings and welcome aboard the CF, Julius.

[rotrax]

We had a 16,000 btu Cruiseair A/C on a previous Island Packet. A Kipor 2600 would run the A/C. It was noisier than a Honda, but less than a third of the price. It gave five years faultless service.

[boatpoker]

We can run our 16,000btu a/c from our small 2400Watt Yamaha generator which is significantly quiter than the Honda.
No soft start, no problem.

[Rumrace]

The Yamaha 2400 sounds nice.
Do you mount it on a swim platform or on shore.

[boatpoker]

Originally Posted by Rumrace

The Yamaha 2400 sounds nice.
Do you mount it on a swim platform or on shore.

Neither ....

[skipmac]

Originally Posted by Bill Seal

believe almost all portable generators only provide 100W (8 AMPS) of power at 12VDC, so you would have to use some sort of ac to dc charger.

I have a Honda EU2000, the older version. It will put out a steady 13 amps, 16 amps or more surge.

It will run a single 16kBTU air conditioner but even with a Victron inverter with boost I had to install an EZStart to handle the high current when the compressor first kicks in.

With this setup I can run the air con until the Honda runs out of gas.

[skipmac]

Originally Posted by Rumrace

The little Honda will run a microwave that’s it. Air on a boat on anchor costs $30,000.00 here period the end. $20,000 for the Onan and $10,000 for air

Maybe give my setup a try. $1000 for a Honda EU2200, about over $2500 for 16kBTU air conditioner, water pump, through hulls EZ Start and a few odds and ends Works just fine.

[boatpoker]

Originally Posted by skipmac

I have a Honda EU2000, the older version. It will put out a steady 13 amps, 16 amps or more surge.

It will run a single 16kBTU air conditioner but even with a Victron inverter with boost I had to install an EZStart to handle the high current when the compressor first kicks in.

With this setup I can run the air con until the Honda runs out of gas.

Yup ! My Yamaha 2400 pumps out 20amps and can handle startup surge.

[skipmac]

Originally Posted by boatpoker

We can run our 16,000btu a/c from our small 2400Watt Yamaha generator which is significantly quiter than the Honda.
No soft start, no problem.

This got my attention. Thought about upgrading from my Honda but looked at the spec. Yamaha 75 lbs vs 48 lbs for my Honda. Since I store mine and lug it up to the stern when I want to use it that extra weight is a bit daunting.