Inverter install questions

M

Morgan Jane

Active Member
Sep 10, 2010
423
Occoquan, VA
Boat Info
2008 55 Sundancer
Engines
Man 900's
I have read thru every post that I could find on the this subject. However, haven't been able to find an answer to this question. I would like to install an inverter for powering the 120 volt outlets on both sides of the boat so that I don't have to run the Gen. while under way. The main reason for this is because my entire sound system is AC voltage now. There are only 4 batteries on a 2005 48 Sundancer. 2 Big Batteries that do everything except the Bow thruster. and 2 12 volt batteries wired in series to power the 24 volt bow thruster. Can I just hook the inverter to one of the 2 Big 12 volt batteries? or do I have to have a seperate set of Batteries for the inverter? Otherwords, can I have an Inverter hooked to a battery that is simultaneously being charged by the alternator on one of the engines? Does this cause a problem? I plan on buying the type that has the built in transfer switch that senses if AC is availble or not.

Bill
 
You'd want to hook it up to the "big" house batteries. not to the 24v bow thruster batteries
 
Thanks 390x. I had planned on hooking it to one of the two big batteries. Preferably the one that is the "house" battery. Just want to make sure that it is okay to convert DC to AC at the same time the DC battery is being charged by an AC to DC engine alternator. All the applications I have seen seem to have a seperate set of batteries that would only get charged back up once you are back at the dock and plugged in. thanks for the reply.
 
There might be a reason for the separate bank. My inverter has 4 x 6 volt batteries and they are only charged when shore/gen. is going, no connection to the alternators at all.....
 
I can't find the user manual for a 2005 48DA (this boat doesn't seem to exist), but I did look at the 2006 manual (are you sure of the year of your boat, or a typo maybe)? Assuming your boat is the same as the 2006, you do not have a dedicated set of house batteries, rather two isolated batteries for the port and starboard engines, which also serve the 12 volt house requirements.

You did state your use of the inverter would be while under way, but if you plan to run a lot from battery when not underway and without having the genny on, ideally you would have a dedicated bank of batteries for the inverter. It would be good if you could put all your house loads on this bank as well...I didn't look through all the schematics to see if this is feasible given how the 12V DC requirements are split between the two batteries.

Regarding the wiring to your existing system, you could wire directly to either port or starboard battery, or to both through a disconnect/selector switch. Most likely your port and starboard batteries are charged via their respective alternator. Not sure about the 24V charger...maybe via one of the alternators and a converter. There would be an isolator in between as well. If you add a dedicated bank of batteries, it could be charged by one of the alternatorsi via an isolator too, in addition to your AC converter (assuming you have an available output, which you may not).

You can use the inverter while an alternator is charging the battery. The DC inputs are usually spec'd somewhere around 10-15V DC with under- over-voltage protection.

Are you planning to manage your AC loads from the inverter manually, or install an AC sub-panel?

Do you know how your 12-volt loads are allocated between the two batteries? I assume all the house requirements come from the starboard battery so you can't inadvertently fully discharge the port engine / generator starter battery. If so, you would hook your inverter to this (starboard) battery. You could also wire up one or more additional batteries in parallel to the starboard one to act as a house/inverter bank rather than having a completely separate bank. The disadvantage of not separating the house and start requirements is the batteries would all need to be of the same crank/deep cycle combo type since they are charged together. The combo type don't last very long if deeply discharged frequently, and non-cranking deep cycle batteries are better for house/inverter use.
 
One more thing...it is safe for the inverter to operate while the alternator is charging, but you have to make sure the alternator itself has sufficient output capacity.
 
The system we have is 10 six volt golf cart batteries (House), four 12 volt deep cycle start batteries. Under way we charge the six volt from one engine along with two 12 volt. There is an automatic cross over (Electitian said it was original to the boat) from the other two 12 volt that will bleed power to the two 12 volt that are connected to the six volt. It has been this way for 5 years and so far have not had any problems. We run micro wave and electric kettle underway. At anchor we disconnect the 12 volt from the six volt. All the switching is done by relays with switches located in electric pannel. I did not instal the system it was done by an electrian. Others I know have put an other 100AMP alternator on one engine that only charges house batteries. The system I have was simpler to instal as it is all relays using existing equipment.
 
I bought my boat in Stuart, Florida in late 2007, and collected it in January 2008. I spent 7 days travelling down the ICC to Fort Lauderdale for shipping to Europe, and was immediately struck by the inadequacies of the house battery system.
Every morning, one engine (starboard from memory) would not start without using the emergency start switch, due to the fridge and lights having dropped the charge from the battery, and if I woke early and wanted to use the coffee maker, I had to start the Genset, not good in a quiet anchorage. It should be noted that the engine batteries are still in use 3 years later, so their condition was not an issue.
I had intended to convert the boat to 220 volts for Europe, but early investigation showed that to be unnecessary, expensive and messy, so opted for a pair of 3.6KV 220 – 100 volt transformers in the transom locker, they are lighter than the pair of 100 volt cables that the boat came with. There is a transformer fitted to each Line, One and Two, for shorepower.
When I got the boat back to the UK, I fitted a Victron 100 volt 3000W Invertor Charger, mounted where the original battery charger is fitted to the engine room forward bulkhead, a Victron battery monitor, (an invaluable piece of kit) mounted in the panel next to the main DB Board and easily visible all the time, and a 120 amp alternator on the starboard engine. There is also a remote power control panel for the Victron; it is mounted in a locker by the main DB Board.
The Victron also supplies a Float Voltage charge for the Engine batteries and Genset battery, switched through a simple voltage sensing relay, when on shorepower.
However the main addition to the system was a set of 6 two volt wet lead acid cells inside a custom battery box that is mounted between the two engines just aft of the mid bilge pump / aircon pump. The batteries are linked together to give 12 volts, and the total capacity is 630 amp hours at the 20 amp rate. The box that they sit in measures approximately 15 inches x 15 inches and is 18 inches high. The box has a lid on it, and makes an excellent step down into the engine room.
I then altered the configuration of the Line One and Line Two outputs on the main DB Board.
Line One, which is only supplied by Shorepower or the Genset, supplies AirCon Forward, Aircon Aft and Aircon Pump,
Line Two, which is powered by the domestic battery / Invertor, supplies Refrigerator, Cook Top Hob, Microwave / Convection Oven, Galley Systems, Port Systems and Starboard Systems.
The 12 Volt supply switches have remained unchanged.
Both 100 volt lines also have a supply to a Rotary switch I fitted that supplies the Water Heater, and by setting the rotary switch to Line One or Line Two, the water heater can be run from either, I will explain why later.
In use on anchor, we run the Genset when using the aircon (seldom used on anchor), water heater and oven or cook top, however while these items are being used, the Victron very cleverly utilises all spare amperage to recharge the domestic battery. We find that 3 hours running during 24 hours, (if there is no main engine running during that period) , pretty much breaks even for power requirements and we do that when making toast and coffee in the morning, and whilst preparing dinner in the evening. Coffee and toast can be made from the domestic battery and Invertor if needed, as can a hair dryer be used, televisions run and the fridge is always on. During these times, when the Genset is running, the water heater is on also, we always seem to have plenty of hot water.
When on shorepower, the Victron Power Control panel has a rotary adjustment that enables the system to be set to draw from 4 – 32 amps, dependant on what is available from the shorepower, a feature we found very useful when travelling through France, many of the Marinas had very low power supplies, and everything that is on Line Two can be used, and the Victron smoothes out the current draw, always using anything spare to recharge the domestic battery between load fluctuations, without tripping out the supply.
The reason for the selection switch to run the water heater off either Line, is that if arriving at the boat after several days or weeks away, and initially needing full aircon or heating, as well as water heating, lighting etc, we switch the water heater to Line Two, and the Domestic Battery, through the Invertor, smoothes out the power requirements, otherwise with all air con or heating on, and the water heater, there is not enough power to supply all that is initially needed through Line One.
Whilst at anchor, if we retire for the night at about 90% battery capacity left, it will usually be down to 75 – 80% in the morning. This means the day can continue, and we run the Genset to bring it back up if we are not motoring anywhere that day, otherwise 3 hours main engine running will have the Domestic battery over 95% full again.
The Victron puts up to 80 Amp Hours into the battery initially, either from the Genset or Shorepower, the Starboard engine alternator puts out 75 Amp Hours.
I hope this convoluted explanation of the system is of some assistance, we find it very user friendly, and pretty much serves all our needs. Feel free to post any questions.

Graham
 
I'm not sure if this is hijacking this thread, but Graham, can you tell us what 6-volt batteries you are using? I am looking for some now and can't find anything that comes close to 630Ah. Do you mean each 6V battery is rated at 315Ah (which means you also get 315Ah when you series two together for 12V)? The highest capacity I have found is a Trojan with a 435Ah 20hr rate (and the cost is astronomical at around $400 each!).

Thanks!
 
+1 on what Graham said about the factory power being completely inadequate. Every boat I've owned I have immediately redone a substantial portion of the factory wiring because they way they do it is no good. I always give the gen its own battery that isn't hooked to anything other than the charger, I then put at least 3 batteries on the #1 side of the battery switch, and another battery on the #2 side. I run everything off of #1, and then if it goes dead I can switch to #2 to start the boat, or I can always fire up the genny as it has its own battery as well. The way the boat was wired from the factory, I could run all the batteries dead without doing anything (no switching between batteries).
 
Great, Great answers guys. Just what I was looking for. Bottom line is I want to be able to operate anything that runs off 120 volt while cruising without having to fire up Gen. If I want Air Conditioning, then I will run the Gen. Was just looking to convert some DC to AC without having to add any more batteries and weight to the boat and you guys are telling me that I can hook the inverter directly to the House battery(starboard engine) and operate it at the same time the Alternator on the engine is charging it. Excellent. Thanks a million for your posts. I don't plan on being on the hook much and if I do, I will run the Gen. I plan on doing a few cruises to FLA in the next couple years and it just didn't make sense to have to run the Gen. the whole time. Thanks again guys.

Bajturner, not sure why you couldn't find the 2005 48DA manuals. That is the boat I have. It was the first year of the model. Regardless, everything you described in the 2006 48DA is exactly how my boat is. thanks again for your post.
 
Good luck with your upgrade. Not a trivial install...you will certainly be well-served with some professional advice along the way. Be sure to share any new information you uncover as you go!
 
bajturner said:
I'm not sure if this is hijacking this thread, but Graham, can you tell us what 6-volt batteries you are using? I am looking for some now and can't find anything that comes close to 630Ah. Do you mean each 6V battery is rated at 315Ah (which means you also get 315Ah when you series two together for 12V)? The highest capacity I have found is a Trojan with a 435Ah 20hr rate (and the cost is astronomical at around $400 each!).

Thanks!
Click to expand...

I installed Trojans and was able to swing a good deal on them but I bought the 12v version (J185H) that have 225Ah at 20hrs but I have 2 on the house side and didn't have to even revise my cables.
 
This is the Xantrex unit I plan on installing. Any issues you guys see with this unit? It is their 3000W version. I plan on talking to the Xantrex guys before I start anything.

FSW-NewGen-151x111.jpg
 
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Hi bajturner

The batteries I installed in my 400DA were 6 of 2 Volt Fiamm wet cells, linked together to give 12 volts and a capacity of 630 amp/hrs.

I have sold that boat and am now in the process of updating the domestic electrics on my 2002 460DA.
I am going to remove the 2 x 12 volt batteries that currently service the starboard engine and the domestics, and will fit 4 of Rolls
600/450AH Rolls 6V Renewable Energy Deep Cycle Battery

Features:

  • 600 AH (C100) / 450 AH (C20) - C100 and C20 relates to the capacity in Amp Hours of the Battery when discharged over a 100 Hour Period or a 20 Hour Period (the slower the discharge the higher the reserve capacity)
  • Enveloped separators
  • 6volt
  • 19 Plates to a Cell
This should give me 900 amp/hrs at 12 volts, and they have a smaller footprint than the existing two start / domestic batteries.

The key ingrediant to the system is an efficient battery monitor so that at all times you are aware of the amount of power you are using, and the exact state of charge / discharge that your batteries are at. The information this gives leads to a very good understanding of power management, and as long as that monitor is easily visible during normal occupation of the boat, and not buried in a cupboard somewhere, it becomes second nature to keep a check on what the domestics are using, and to manage it more efficiently at any time.

We found on the 400DA that over a 24 hour period, we ran the genset 4 hours, usually 1 hour in the morning, 3 hours in the evening and this gave us full batteries and endless hot water, and by timing the genset runs with using the oven, hob, air conditioning and or toaster, it was not a problem. Obviously if we motored anywhere, the genset running was a lot less, and the 120 amp alternator on the starboard engine took over the recharge duties.

Graham
 
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Morgan Jane

There would be no problem with your plans, however you really dont want to run your batteries below 60% of their capacity, so you would not have the capacity that I want, but a number of items would still be available to use without the genset, coffee maker, hair dryer, sound system etc.

I still think that an important addition is a battery monitor, so that you know exactly where your batteries are at in any given time.

Also converting all 12 volt lights to LED bulbs is a massive saving of battery power, you will be staggered by the amount saved every evening spent on board.

Graham
 
Morgan Jane said:
Any issues you guys see with this unit? It is their 3000W version.
Click to expand...

It's a great unit, but a ton of inverter for one battery. Your design would be a little imbalanced in that regard. You would be trying to draw close to 300A from your one 12V battery at full-load! This just wouldn't work. Even at half load you would drain a dual-purpose battery in no time. The Xantrex people will be able to give you some realistic battery bank sizing, I would think.

Also, if you are not an electrician, or extremely competent electrically and with boat power distribution, I wouldn't attempt installing this on your own. It's not rocket science, but there are correct practices that have to be followed for a safe install on a boat.
 
bajturner said:
It's a great unit, but a ton of inverter for one battery. Your design would be a little imbalanced in that regard. You would be trying to draw close to 300A from your one 12V battery at full-load! This just wouldn't work. Even at half load you would drain a dual-purpose battery in no time. The Xantrex people will be able to give you some realistic battery bank sizing, I would think.

Also, if you are not an electrician, or extremely competent electrically and with boat power distribution, I wouldn't attempt installing this on your own. It's not rocket science, but there are correct practices that have to be followed for a safe install on a boat.
Click to expand...

+1 on both of these comments! Absolutely correct.

Graham
 
Graham Lorimer said:
The batteries I installed in my 400DA were 6 of 2 Volt Fiamm wet cells, linked together to give 12 volts and a capacity of 630 amp/hrs.

I have sold that boat and am now in the process of updating the domestic electrics on my 2002 460DA...and will fit 4 of Rolls 600/450AH Rolls 6V Renewable Energy Deep Cycle Battery
Click to expand...

Thanks Graham. I can't believe I missed the Rolls batteries- manufactured in Nova Scotia! I would imagine they are priced similarly to the Trojans...
 
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