Aircon from Inverter from Batter Charger

[never monday]

Originally Posted by BlueRhapCity

I still suspect it's a bad idea.
This is what happens when computer guys start designing boat systems...

All the more reason to K.I.S.S. run the generator and insulate the engine room well. Come to think of it I've never seen sound insulation short circuit and leave me without navigation lights.

[Agility]

Generator? I had nothing but trouble with my genset. Many folks I've talked too have had numerous problems also. You can't use it at the marina at least not one that caters to sailors. You can't use it at night on the hook, too loud. Yes you can charge you batteries but I can do that more efficiently with the alternators, solar & wind power.

A generator doesn't solve the problem of plugging into US and Euro power to run the aircon.

Maybe it's just me, but I haven't had a positive relationship with generators....

[never monday]

A generator is designed to produce the most power from the least fuel. If you have a 5000W AC generator burning 1 gph on a dedicated engine. You are better off than running your main for the same time with a 300A alternator producing 3600W @ 12V and 1.0-1.5 gph. This saves wear on the main.

The 120/60 Vs 220/50 problem is easily solved with adapter plugs. The wires don't care what the power flowing thru them is. If it's an AC system designed for 120/60 then it will be more efficient at 220/50.
Find appliances that will function on both.
On noise. There will always be some level of noise. A properly installed and insulated generator will be almost imperceptible to the residents of the vessel.
Like I said earlier, I've never seen a failure of insulation shutting down a critical system.
Wind and solar can work well as primary generation on small craft (<30') with minimal demands. But I believe they are only viable to augment your other generation systems on larger craft as the demands for power increase. A typical wind generator can produce about 400w a day. If you have an 800Ah battery bank it's going to take a long time to recharge with wind. Add a 175W panel or 2 and now were up to 750w per day. It almost doubles your available free energy, but will still fall short of demand on a larger vessel.

[Agility]

I did use a simple battery charger interface to get power into my last boat - Agility. No need for an additional isolation transformer and I was able to plug in anywhere in the world and get power. We did not end up installing a air conditioner and were glad to have the universal battery charger that allowed us to run 110V from any dock around the world and on the hook.

The only issue I had was that the battery charger would go into a float mode and then the batteries would drain after a while. I'd turn the charger off and then back on again and get back to full charge. This was probably unrelated but when I would leave the boat I'd get down to about 80% unless I bumped the batter charger to restart the charge cycle.

I'm designing a new boat and am thinking about doing the same thing. I'm considering adding an air conditioner this time and feel like it's the key power consumer that would stress this world accessible power system. So, maybe I need to add a isolation transformer for the air-con so it can draw power directly from shore-power but it weighs yet another 50 lbs and each 50 lbs is expensive on a lightweight cat.

I could do a 240v 50hz air-con and run it on US and on international power and be fine no mater which power I plug into?

What am I missing?

[sailinglegend]

Originally Posted by Agility

....I could do a 240v 50hz air-con and run it on US and on international power and be fine no mater which power I plug into?

What am I missing?

I think you are missing a lot - and getting confused from some comments here.

I do what I think you are trying to do with my VICTRON Multiplus Charger/Inverter. Mastervolt do a similar Combi unit.

These are basically a shorepower charger and an inverter, BUT they can't charge and invert at the same time. On my Victron the incoming shorepower goes via the unit which synchronises itself to the shorepower. If the boat load needs more than the AC shorepower can supply then the inverter supplies the extra from the batteries - even for milliseconds - and then goes back into DC charging mode and normal AC output mode. So if your shorepower only has 16 amp breakers (UK 240V) and you want 20 A then the extra 4 amps will come via the inverter from the batteries. Similarly when the Air Con starts up the AC inrush current needed comes via the batteries. This has been working perfectly for 7 years with my 12,000 BTU Air Con. I also run the air con for 1-2 hours from the 1050 Ah battery bank.

You and jscott are wrong in assuming that a 240 volt 50 cycle system will run better on 60 cycles. When I bought my Air Con the supplier offered 240 volt 60 cycles as a better option if travelling to the US. At 50 cycles it will run slower and cooler with less output, so I decided to stay at 50 cycles.

An inverter may accept 50 or 60 cycles input but will not convert the output from one frequency to another! The only answer is to run from the batteries with the inverter/charger set to inverter only - or at anchor I use a FP 280 amp dc generator.

[valhalla360]

I've looked into a similar system. Assuming the charger and inverter are properly sized, the only issue I haven't figured out is will it kill the batteries in a short time period.

Key points:
- The battery bank is not intended to power the system. It is there to absorb the highs and lows (for seconds maybe minutes not hours). The power goes in thru the charger at what ever volts/cycles is available and out thru the inverter at the desired volts/cycles.
- You can set up the boat using your local power standards (or where you think you will be most of the time) so no worries when you move to a location with a different power source.
- Running generators gets very expensive compared to plugging in. Plus there are those that get offended by the noise (I'm not one of those people)
- It should address a lot of issues with brown outs and other poor quality power connections (assuming the charger has robust input ranges that can handle a wide range of voltage)

So can anyone tell us. If the power is basically just flowing thru the batteries but is replaced as soon as it's used (ie: you never run the batteries down), will it damage them having say 100 amps at 12v constantly passing thru.

[Agility]

Originally Posted by valhalla360

So can anyone tell us. If the power is basically just flowing thru the batteries but is replaced as soon as it's used (ie: you never run the batteries down), will it damage them having say 100 amps at 12v constantly passing thru.

Well said. I think it's the battery charger that's the real question. The inverter should be able to handle things especially if it's a Victron or Mastervolt. But how should I size the battery charger and will I have any issues passing thru the batteries to the inverter. I am planning to get a 12/200 Victron which should pull about 2,400 watts of power from the shore. The separate inverter will do 3,000 watts and have a surge with battery backup. Shore power is 30Amp 110 at 3,300 watts in the US so the battery charger shouldn't blow a circuit. The typical Euro is 16 Amp service fo 3840 Watts so I'm still OK plugged in internationally with enough juice to fully power the battery charger.

If I do an aircon it's about 1,500 watts and If I do an induction stove that's another 1,500 watts max so with an inverter that's rated for 3KW I can get 2.2kw at Cont. output power at 100 °F (W) and Peak power of 6KW which is more than I need for every electronic running at once.

I don't have a genset but am looking at the Yanmer KMG65 bolt on generator. It's 230Vac but I could have it wired into the main shore power switch that gets sent directly to the battery charger.

My goal is to have a system that works anywhere in the world and with no genset. I'll have a ton of solar, LifePo and wind that will hopefully generate all the typical daily power needed.

[sailinglegend]

Originally Posted by valhalla360

....So can anyone tell us. If the power is basically just flowing thru the batteries but is replaced as soon as it's used (ie: you never run the batteries down), will it damage them having say 100 amps at 12v constantly passing thru.

Not sure if I fully understand what you are saying here?

If you take out 100 amps for an hour that's 100 Ah taken out of the bank which must be replaced. If this is say a 20% depth of discharge that's one more battery life cycle that goes towards the death of the battery. A battery might have 3000 cycles at a 20% DoD, but only 1000 cycle at 50% DoD.

[s/v Jedi]

Power output from the charger does not go through the batteries when an equal amount of power is used by an inverter connected to the same batteries.

In that case, power flows directly from the charger to the inverter. The batteries act like a giant capacitor in that case.

[Phoenician]

Referring to your plan to use indifferently US or Euro shore power, have you thought of what kind of shore power inlet you will want to install initially? You may find they are not compatible, which may defeat the purpose of your intended dual usage. Special care must also be taken with the GFCI which I understand have different specs between ABYC and ISO.

My boat came from the US with US AC power (both 110/50 and 220/50), and I've "converted" it to Euro power by inserting a Victron Isolation/StepDown Transformer between shore power and the boat's main circuit breaker. I also had to change over the Marinco US type 220 shorepower inlet (2 lives, 1 neutral and 1 earth) with the international 220 version (1 live, 1 neutral, 1 earth).

The Victron IT is able to run the ACs , which on my boat draw a total of approx 2800 Watts

[goboatingnow]

You won't have any specific issues with the shore power size it for 110 and it will be fine on 230 vac. You could use a flying lead convertor at the end to deal with the pin in compatibility.

EU style RCDs will operate down to 110 check the specs.

Personally I'd prefer two shore power inlets and a " dummy " changeover ( which could switch RCDS if necessary ) it would provide a visual and definitive switchover from the two voltage systems. ( and maybe some nice indicator lights. )

You obviously have to ensure there is no outlets of any kind on the input mains side of the wiring

Run the shore power directly to the charger only. Also in effect handles any reverse polarity issues as the charger will not care. ( I would not connect the incoming AC earth wire into the DC system ) in effect you are recreating a local AC source on boats so treat all earths as local.

( see the thread on isolation transformers ) as in effective you are installing an isolated transformer coupled AC system.

There's no issue with the battery in circuit , nick has covered that correctly

Dave

[valhalla360]

Originally Posted by sailinglegend

Not sure if I fully understand what you are saying here?

If you take out 100 amps for an hour that's 100 Ah taken out of the bank which must be replaced. If this is say a 20% depth of discharge that's one more battery life cycle that goes towards the death of the battery. A battery might have 3000 cycles at a 20% DoD, but only 1000 cycle at 50% DoD.

I think the others have answered my question (it shouldn't be a problem)but for clarification:

The battery bank will never be down 20%. If you pull 100amps out of the batteries, the charger is continously putting 100amps into the batteries (after accounting system losses of course). Think of the battery like a bucket with a hole in the bottom and a hose running water into the bucket. As long as the hose puts water into the bucket as fast as it leaks out the bottom, the bucket never empties (ie: the batteries never drain). The question was does the mear fact that water is flowing thru the bucket, damage the bucket?

Obviously, if the charger fails (fuse blows, plug gets disconnected, etc.), it would probably be a good idea to incorporate some sort of alarm or automatic disconnect. That 100 amp draw would kill the batteries quickly if the inverter keeps chugging away.

[valhalla360]

Originally Posted by s/v Jedi

Power output from the charger does not go through the batteries when an equal amount of power is used by an inverter connected to the same batteries.

In that case, power flows directly from the charger to the inverter. The batteries act like a giant capacitor in that case.

Thanks, that is what I was trying to verify.

[valhalla360]

Originally Posted by goboatingnow

You won't have any specific issues with the shore power size it for 110 and it will be fine on 230 vac. You could use a flying lead convertor at the end to deal with the pin in compatibility.


Dave

Good point. If you have a european boat and want to convert to 110, be prepared to replace all of the actual wiring as it runs at roughly double the amperage when you cut the voltage in half, so it's likely to be undersized at the new voltage.

A 110 system can be converted to 220 more easily as the wiring only has to take half the amperage it was designed for. The main panel and all the outlets need to be considered but it avoids snaking wire thru hard to reach areas.

[rjtrane]

If starting fresh, I support the idea of using inverted power on board. Our current boat Sunshine is set up to use ONLY inverted power.

1. Shore power goes thru a breaker directly to a 3kW charger.
2. The battery is 1,000 AH/48v. Lower voltages would work OK.
3. I have 2 each, 3.6kW Outback 120 VAC inverters. These could be rigged to supply 240 VAC if desired.
4. ALL 120 VAC is perfect 60 Hz regardless of quality of shore power. Also, no voltage drop either.
5. On board charging is from integrated flywheel DC generators on each motor. Alternately or in addition, a stand alone variable-speed DC generator can be installed.
6. Also, a sizeable solar array fed through Outback controller chargers charge the battery.

We have both 8 kBTU and 12 kBTU air conditioners, two 1,800 w induction cooktops, microwave, Splendide washer/dryer, 14 cubic foot Hitachi fridge, 11 gallon hot water, 7 gallon GPH water maker - ALL running on inverted power (not at the same time).

We easily go overnight with one or two A/Cs running w/o the diesel running.

I feel that this offers a very good user experience. There is NO changeover when unplugging and leaving the dock or when starting/stopping a generator. The inverters are happily running 24/7 as is the charger when plugged in. Since launching this season in November, she has yet to be plugged in.