Re: [Amel] Battery Chargers and Inverters

Steve Constantine <svsummerlove@...>

Hi Kent,

Summer Love (SM340) has the same size battery compartment that you probably have on Kristy (i.e. 8 - 12V size 30H Trojan SCS225 house, plus 1 starting).  I seem to remember Joel telling me that he had convinced Amel to increase the size of the battery compartment on the later model SMs (please correct me if I'm wrong on this, Joel), which would explain why Paul is able to fit 12 of them and we can't.  If "Kristy" doesn't have the larger compartment, you'll be limited to 9 batteries.

I'm curious why you feel you need a 4KW inverter when your boat already has a perfectly good 7KW genset.  When I wired my system I used the schematics in the Amel manual, so I have the same configuration you have.  In other words, the inverter is only wired through to the microwave and 220VAC outlet breakers at the distribution panel.  The rest of the breakers are isolated from the inverter, and only receive AC power from the shore cable or the genset.  Amel knew what they were doing when they designed it this way.  The purpose of the inverter is to provide AC power when it isn't practicable to start the genset (i.e. warm up then cool down).  This would apply to a few minutes of microwaving, making toast, drying hair, vacuuming up some crumbs, or mixing a frozen drink in the blender. Anything longer than that, such as doing laundry running the dishwasher or the A/C, making/heating water, etc., and it's worth your while to start up the genset.
 Since all these longer functions can be planned in advance far easier than say, satisfying your craving for popcorn in the next five minutes, you can group them together at a time when the genset would be running anyway around mealtimes or to charge the batteries. The benefit of this is that you really only need an inverter capable of short-duration, relatively low amperage operation; and you can still run the genset at a high load for efficiency.

I also don't understand the need for multiple 100A chargers when you're only consuming 130AH per day.  Chargers and inverters are notoriously inefficient to begin with, never mind having capacity you can't really use.  I have a 520A battery bank, which means at 130AH I'm using 25% of my total capacity per day.   Batteries charge most efficiently from 50% to 80% of their capacity.  After that, more and more output current from the charger is required to input less and less into the batteries.  It's a little like blowing up an air mattress or dinghy... at first it's easy to pump and a lot of air gets in quickly, but the nearer you get to full capacity, the harder it is to pump and less air is being forced in.  So, if you can replace your 25% by charging from 55% to 80%, you'll be a lot more efficient than charging from 75% to 100%.  Trojan recommends a charging current of 10% to 13% of bank capacity for flooded batteries (20% for AGM).  I
installed two 30A Xantrex 2430 chargers, which can be "stacked" to run in parallel for a total of 60A.  With the aforementioned "air mattress effect", the best I can usually get is an average charging efficiency of 43AH per hour.  If I charge twice a day, I need to replenish 65AH each time... or about 1.5 hours, which coincides with the wash cycle on the washer or the time required to make about 240 L of water.  

I chose to go with separate inverter and chargers.  When I'm on shore power, I can just use one of the 30A chargers, which also gives me a spare in case one or the other fails.  I can then send the defective one for repair without losing my inverter with it.  The other thing to remember is that a 4KW inverter draws about 250A.  Unless you want to go into a sideline business smelting aluminum or something, that's an awful lot of power.  Due to the interference noise that can be generated by inverters and chargers, I chose to install them in the engine room, because I wanted them well away from the the nav station electronics and exposure to water in the wet locker.  To prevent voltage drop at that distance, I ended up with 16' of 1/0 cable in each direction and a 100A fuse for the 1800W inverter.  Had that been a 4KW inverter, I'd be looking at 4/0 cable or larger and a 300A fuse. This would have required much larger cutting and crimping tools,
not to mention the cost, weight and the challenges of working with that size cable.

As far as I can recall, I don't know of any inverters that override the shore power or genset, although they could be rewired to work that way.  That said, I checked the Amel schematic (Schema Detail K1-K2).  IF you have the original Amel installed 1200W inverter, AND they wired it per this schematic, it appears the K2 relay operates when 60/50Hz shore/genset power is sent to it, which then cuts off the 50Hz inverter AC to the microwave, and replaces it with shore power.  The connections feeding the winding of the K2 relay are downstream (on the appliance side) of the master 32A breaker mounted on the side of the 220V distribution panel. If you turn off that breaker, it will drop the K2 relay and you should still get 50Hz AC from the inverter to your microwave and 220V outlets, while at the same time disconnecting power from all the other breakers.  It will at least save you having to go out on the dock to unplug it.  To verify if this will in
fact be the case, connect a voltmeter to one of the 220V outlets (you should get 220V). Then turn on the dishwasher breaker on the panel (the light should illuminate on the dishwasher).  Turn off the master 32A breaker (you should see a quick disappearance and return of voltage on the voltmeter as the K2 relay cuts the 60Hz off and applies the 50Hz from the inverter, and the dishwasher light should go out).  You could also disconnect AND CAP the wires going from the breaker panel to the K2 relay, which would give you a permanent inverter fed microwave and outlet configuration.  Just remember to reconnect it when you get to a place with 50Hz shore power.

Hope this helps,

Summer Love
Currently Grenada

From: Kent Robertson <karkauai@...>
To: "amelyachtowners@..." <amelyachtowners@...>
Sent: Sunday, February 24, 2013 1:42 PM
Subject: [Amel] Battery Chargers and Inverters

Thanks, Richard.  I've been looking at all kinds of chargers and inverters.  It seems that it's hard to find an inverter that doesn't have a charger too.  There are plenty of inverters that have 220 outlets on the machine, but the ones that are built to be incorporated into the boat's systems all seem to be charger/inverters.  The cost of separate charger and inverter appears to be something on the order of $1000 more than a charger/inverter combo.  The Magnum that Paul has is about right with 125A charger and 4000W inverter.  It's a great price but I'd like to hear from others about it's reliability and service record.
I've been looking at his battery bank post, and can't find any group 31 batteries that are rated at more than 110-120 amp hours (UltraPower does have some very large 200-220AHr batteries that weigh 95Kg) 215 amp-hr group 31 batteries really exist?  Are they gel cell, amg, or flooded lead acid?  The idea of having 3 times as much battery storage is intriguing, but I'm beginning to think that something isn't right about Paul's calculations???
I'm not worrying too much about 110 AC power.  I have a 1000w inverter at the nav station that supplies my needs for charging electronics, etc, and am using 220 appliances for everything else.
Is it your understanding that even though an inverter produces 50Hz AC power, if there is 60Hz coming into the charger/inverter from shore power, it will pass that through to the appliance rather than use battery power and inverter to produce 50Hz AC power?  Perhaps some of the newer combos have a way to program one way or the other?  The only difference it makes is that when I'm connected to 60Hz shore power and want to run the microwave, I have to disconnect shore power and run off of the inverter to avoid the 60Hz power reaching the appliance.  On my boat, only the microwave and receptacles are powered by the inverter, the other appliances and A/C and water heater must be powered by either the genset or shore power.
Electricity has never been my strong suit, and I'm learning as I go....but this stuff seems more difficult to sort out than it should be.
SM 243
Currently Brunswick, GA

From: Richard03801 richard03801@...>
To: "amelyachtowners@..." amelyachtowners@...>
Sent: Sunday, February 24, 2013 10:37 AM
Subject: Re: [Amel] Re: Splitting The Battery Bank

Hi Kent I would suggest that you buy a Charles or charger that's a smart charger that can accept 9p to 260 V and 50 or 60 Hz this will allow you to charge the battery no matter where you. Second I would buy a inverter and mount it outside the engine room perhaps at the nav station close to the batteries. Normally you will want a battery charger that will charge at an output of least 10% of the amperage required for the battery bank.
Placing a heavy load such as the AC units on the battery bank is a very high use of Amp hours and may cause batteries to overheat on the long-term.
Running the AC units off the gen set or shore power is probably a better solution.
To run your 110 v 60 cycle things you may need to wire the boat for some 110 plugs and run those from an inverter off the battery bank that gives you 110 V 60 cycles and a smoothly.
Good luck smooth sailing


Richard Piller

Cell 603 767 5330

On Feb 23, 2013, at 13:06, "Kent"> wrote:

Hi, Paul, et al,
I am looking to replace my old Heart Interface charger/inverter and am interested in the Magnum MS4124E. Your post below is very interesting and I'm thinking of doing something like this on Kristy (SM 243). I'd like to pick your brain a bit.

How do you like your Magnum charger/inverter now that you've had it for a while? Any idea what their service is like?

I currently have 8 105amp-hr series 27 lead acid batteries hooked up in 4 series pairs to give me a 420 amp-hour bank. I charge for about 1 1/2 hrs twice a day. Do you have a pic of your battery crib that shows how you squeeze 12 series 31 batteries in and how you have them wired? A wiring diagram would be great if you have one.

I virtually never use the A/C's unless hooked up to shore power. When I was hooked up to 60 Hz shore power, the old Heart Interface passed the shore power through to the microwave and receptacles, so if I wanted to run the microwave I had to disconnect shore power and use the inverter to get 50Hz 220 power. The washer/dryer, dishwasher, and A/C's are hooked up separately and do not receive power from the battery bank/inverter. I've always run the A/C's with 60Hz shore power, and in 5 years have only replaced one capacitor. I would like to be able to run them off of the inverter, but with my old Heart Interface, the shore power was passed through preferentially over the inverter. Does the Magnum do this or does it produce 50Hz power even when hooked up to 60Hz shore power? Does running the inverter continuously for the A/C's create any problem for the batteries or the inverter?

Thanks for any thoughts you might have. Please, others chime in as well.
SM 243

--- In, "LaFrance" wrote:

We recently split our battery bank into 2 separate units mainly for charging purposes.

Our vessel is used 12 months of the year and is rarely on shore power. Amel provided the vessel with 12-12V lead acid house batteries with a Dolphin 100 Amp charger and a 30 Amp Dolphin charger. The 30 Amp charger is used for when connected to shore. Our research indicated that a 100 Amp charger is good for charging a battery bank of up to 400 Amp/Hrs. We currently consume 130 amp/hrs per day

The Dolphin charger was not of sufficient capacity to maintain the battery bank at the levels for charging. As per the Trojan Battery Company's charging and maintenance guide the charging voltage daily during absorption should be between 29.2V – 29.6V.( To accomplish this on the Dolphin, the #2 setting (which gives 29.6V) was selected. Due to line loss, the voltage to the batteries is 29.2V. We confirmed this with the USA representative in Florida. There are no settings available on the Dolphin 30 Amp charger to provide this voltage.

Our current Amp/Hr capacity is 1,290 Amp/Hrs (12 X 215 Amp/Hrs divided by 2) The batteries are type 31 made by UltraPower.

As we saw it the 100Amp charger was not sufficient to do the job hence splitting the batteries into 2 banks to 645 Amp/Hrs in each bank. The 100 Amp Dolphin charger still would not do the job as there are more than 400 Amp/Hrs. We then decided to install another battery charger with inverter capabilities. We chose a Magnum MS-E Series Pure Sine Wave Inverter/ Charger Model # MS4124E. This charger provides 105 Amps of charging power. We note that we get 114 Amps when charging (Bonus) The inverter provides us with 220V 50 Hz power to run the appliances on board without having to start the Genset. Cost of unit with remote control, temperature sensor & shipping $2,066.41 USD.

Now we can charge each bank with sufficient Voltage and Amps and it takes half the time when using both chargers. Other stand alone marine chargers were much more expensive and did not have the inverter function. Magnum chargers are mainly made for the trucking industry and do not carry the marine markup that we often see in place. The Magnum charger is a much smarter unit than the Dolpin in that it allows adjustments and tapers off when charging with Dolphin charger. When the Genset output is done to 14 Amps we turn off the Dolphin and leave the Magnum on as it is smarter and charges the batteries properly after the bulk charge.

As a result of the split we installed a Link 20 monitoring system to check the banks. The old Link 10 monitor now does the 12V starting battery. We also had designed another monitoring system by Blue Sea to monitor the output from the genset which has a 30 Amp breaker. When running both chargers the genset is putting out 29 Amps. As you may be aware a fully loaded and working diesel engine likes to be loaded up and will last longer. When charger is half done then we can turn on other 220V systems. This unit also tells us how the genset is working and when it may need repairs to the electrical part of the genset. It also allows us to monitor the draw from individual units on board and we can fix if we see a drop or increase in what the particular system is drawing.

This project took over 3 years to design and understand the Amel systems with a lot of input from people far more knowledgeable than us.

We now use one battery bank every 24 Hrs and then switch to the other bank ( bank 1 on odd days and bank 2 on even days)

Less time charging the battery banks saving genset hours, fuel and maintenance
Inverter can supply power to 220V/50Hz systems without genset having to be run
When hooked up to shore power either 110V or 220V 50 or 60 hz the charge is run through the Dolphin 30 Amp charger and we then use the inverter to obtain 220V/50hz for our power needs on board. As a note the Air conditioning units require 50hz contrary to what Amel says. We checked with Clima on this and they stated on numerous occasions from different technicians that the capacitors will blow out. (As a side note when we were on shore power in the US we ran the Air Conditioning units and as a result had to replace 12 of the 15 AC capacitors as they were blown and not functioning) As we normally only have 110V/60hz or 220/60hz available we took this route. The added benefit of the Blue Sea unit is that it tells us what type of power is coming on board either 110/220V & 50/60hz
We can monitor what each unit is drawing on both the 24 V and 220V systems IE: Washer/Dryer, AC units, Bow thruster, Winches, Furlers etc

We now have the capability to know what is going into and out of the batteries. With the batteries being able to rest for 24 Hrs, we feel they will last longer and will not require equalization. We did not keep track of all the costs but installation took approx. 20 hours along with a lot of wire.
Magnum Charger $2,066.41, Link 20 $375.15, Blue Sea Monitor $875, 12 Batteries $1,285.48

As a side note the Dolphin 100Amp charger has an equalization setting. When we asked the Florida technician, he then inquired to France and they stated in no uncertain terms by email to not use it. We are on our 3rd Dolphin charger replaced 2 under warranty and 1 due to water damage when the water maker high pressure hose blew. It appears that the charger is set up for charging 2 separate banks but the divider breaks down over time. This was even before we installed the additional charger. Warranty work is dismal as they had to send units to France then on to the manufacturer. Our last warranty unit took over a year to be returned and we currently have one in for warranty since October 2010 and they don't know when we will get it back. The company is owned by REYA and they have some one else build them in Europe we think but can't confirm who. The USA representative is looking for another source to provide warranty work as REYA's contract expired in
December 2010. The Florida representative, Steve, has been more than helpful. His hands are tide and the company has tried on our behalf and numerous others to get info which is not coming back to them. When they ship the units back they go on a pallet as there are so many. No wonder they are looking for a new warranty provider. Who needs this type of customer service.

Paul LaFrance
SV NOMAD SM 362 Currently in St Lucia
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