Bob, this may be of some assistance: [url]http://c34.org/bbs/index.php/topic,833.msg3788.html#msg3788[/url]

Bob:

I hope this is of some help as well. As I write this we are on anchor and I have onboard a prosine 2.0 inverter. This is given our system a test. I have 4 T125 trojan batteries for our house set up. Motoring we are able to run everything we have on board. I have a Balmar 90 amp regulator for motoring.

The 1000 watt micro wave, coffee pot and fry pan with out any trouble. But at anchor, no microwave or coffee pot or fry pan. Everything else is a go. But on anchor we switch over to using the stove for coffee and cooking.

Randy

[QUOTE=therobesons;2207]
Now, how to install, just remove old charger (no inverter) and install this unit or is it a lot more complecated than that? That is the question.[/QUOTE]

Bob, you're talking apples and oranges here. An inverter is not a charger and doesn't replace it. I recommend that you read the West Marine Advisors in their catalogs or online (here: [url]http://www.westmarine.com/webapp/wcs/stores/servlet/topcategory/10001/-1...) and learn about what they do and how they work.

Based on the recent post, the sizing of both the inverter and your house battery bank is critical to the success of the installation. mY earlier link discussed the choice of connecting to the house A.C. system and the switching required if you do so.

Yes, you're right a combination inverter/charger ("I/C") is a completely different animal than the separate charger and inverter setups. However, if you read back you originally said you were planning on "adding an inverter" so you've kinda switched your tune.

If you are changing to an I/C, then dump your charger and install the I/C which will have its own internal switching, just follow the installation instructions carefully. You have to remember that the I/C is "replacing" the A.C. power to the boat's A.C. system when you're off shorepower, so the A.C. wiring route is important to understand: it's either the inverter providing the A.C. power OR the shorepower, then to the A.C. master switch on the panel.

If your charger is toast or no good, this is a good move. If your charger is a good one, it may be less expensive to just add an inverter, but I assume you've done that analysis.

I have a 1985 with an Exide I/C 2000 watts. Some cautions. My battery banks are 210 AH ea. As general rule you shouldn't run down your batteries below 50%. In my case that's about 105 AH. My Mr Coffee pot uses just about 10 AH to make coffee before it shuts itself off. I have the thermal carafe style no hot plate in the base. My toaster uses about 8 AH to make 2 slides of toast. As you can see making toast and coffee consumes almost 18% of my working battery capacity. The good news is I have solar panels so generally I'm not too concern.

A couple of key points to bear in mind. Review you AC wiring carefully with an eye to isolate the water heater circuit. If you have the inverter on and accidently have the heater on you will run down your batteries in a heart beat. A 1500 watt unit at 120 VAC will burn 12.5 AMPs from an AC source or about 125 AMPs from a 12 VDC source. 1 hour will run you bank down. Also anything else you have plugged in, i.e. battery chargers for cell phones and computers will rob some additional amps.

At anchor in the evening, the anchor light and refrig are on all night plus reading lights until your asleep. If you run a TV or stereo you will consume AMPs whether AC or DC powered. I mention this because by 8:00 pm you will rarely have topped off batteries. Your morning cooking will drain power from a lesser capacity than you fully charged batteries.

All that being said, it's a good choice I believe 2000 AH is a good compromise for boat our size and battery bank capacity.

Nice system you have , although overloaded with what could be considered A.C. dependent accessories.: "[I]A couple of key points to bear in mind. Review you AC wiring carefully with an eye to isolate the water heater circuit. If you have the inverter on and accidentally have the heater on you will run down your batteries in a heart beat."[/I]

The heater is part of the A.C. side of the panel, so all you need to do is to remember to NOT have the dhw heater breaker ON.

Which you should do MOST of the time anyway, 'cuz it only takes 20 minutes or so to heat water from A.C. power, then turn it OFF.

Do an energy budget and work it out for what works best for you. There's no one right answer.

My point, Stu, was DYI wiring and carelessness can cause a problem. I do not have a microwave, TV or other high draw AC accessories. I just happen to like a cooked breakfast.

Regards,

Lou

The P.O put a 2000 Watt inverter/charger on our MKII. I typically do not run loads of greater than 1000 watts however, because the current draw on the batteries will cause the voltage to droop far enough to trip the inverter if I try to run it at full capacity.

I also tempt the gods and turn the battery switch to "both" while running high loads.

(eventually, I will put our two 4D batteries in parallel and add a starting battery, unfortunately, the inverter large and is in the forward starboard settee where most folks put a starting battery.)

If I am running a high load for an extended period, I will run the engine. Although our 50 amp alternator will not keep up with a 125 Amp load, it will keep the voltage up and I will run the motor for another 20 minutes recharge the batteries.

We use ours for:
coffee. ~ 1000 watts/ 5 minutes
Hair dryer - 1200 watts/ 10 minutes but only with the engine running, which serves the dual purpose of heating the water. (we deliberately purchased a low wattage hair dryer BTW)
Microwave ~ 1200 watts/ five minutes
Random non battery powered power tools. (It will run a buffer nicely)

Bottom line
If I were doing it myself, I would probably go no larger than 1500 watts, since the 4D batteries really can't produce enough current to drive more than that, and I would be sensitive to the size of the unit, so that I could still mount a group 24 starter battery in the settee.
Dave

[QUOTE=dwarburton;2238...I would probably go no larger than 1500 watts, since the 4D batteries really can't produce enough current to drive more than that, and I would be sensitive to the size of the unit, so that I could still mount a group 24 starter battery in the settee.
Dave[/QUOTE]

Dave, that's simply not true. A 4D battery provides about 150 ah of capacity when full. The inverter load is simply transferred as an amperage load to the D.C. system --- time of use X current drawn in amps = amp hours. So a 2000 watt inverter at full load will simply draw more than a 1500 watt unit. You can do the conversion factors from watts to amps. Point being that the amp hours capacity of a bank has little to do with the draw it can withstand. Of course, a 100 amp load for 5 minutes will affect a battery differently than a 5 amp load for 100 minutes, but that's another story about battery rating standards.

Stu,
Let me clarify my point. Assuming an 85% efficiency of the inverter, a 2000 watt load draws about 2,350 watts from the battery.

At 12 V, the draw is 196 amps
At 11 V, the draw is 213 amps
At 10 V, the draw is 235 amps.

There are two issues. First, at high current draws, the internal resistance of the battery causes the voltage to droop, which will cause the inverter to trip, even if there is still plenty of capacity in the batteries. The internal resistance is a function of the battery size and age. Larger and newer batteries have a lower the internal resistance. That is why I use both batteries when I run the inverter, it cuts the internal resistance in half, reducing voltage droop.

The second issue is that the capacity of a battery is not a fixed number but is a function of the discharge rate. (The relationship is defined by Peukert's law if you want more detail.) So, at these high discharge rates, the AH capacity of a battery can be less than the rated capacity.

Based on the size (4D) and age of my batteries, I find that the voltage droop at anything over about 1200 watts output load will pull down my batteries to under 11 volts in only a few minutes of use, especially if they are not fully topped off. I have never run the inverter at full load, for this reason.

For what it is worth, I second all of Dave's comments in his last post.

Dave:

I am a 2nd one to agree with you. I have the prosine 2.0 and followed the installation by the book and used the correct cable size which is HUGE for what I thought, but I figured Xanterex knew what they were talking about.

I have 4 new T125 TROJAN batteries and just out of spite, I wanted to see what the 1000 watt micro wave would do. It is not worth it to me on anchor to run it so the only time we use it or coffee e pot of frypan is when motoring. Other then that everything else is OK to use.

Randy

For what it is worth, I THIRD all of Dave's comments in his post #14!!!

Really, we're in agreement, since I mentioned the 100/5 5/100 at the end of my last post. If you have old tired batteries that won't hold a charge or keep their voltage up, then your approach is very wise. It didn't necessarily deal with the issue of sizing the inverter, but brought up a very valid operational issue.

[QUOTE=therobesons;2285]What happens if you spperate the currant charger from the 110 volts, so when on shore power you have NO AC, only battery charger, then hook up the Inverter only to the AC.

Would the inverter (prosine 2000) be able to supply enough AC to run the micro, coffee pot etc while it is hooked up to the charger/shore power?[/QUOTE]

Bob, if you have a combined I/C the inverter function is not used when connected to shore power. The I/C is "smart" and knows when shore power is available, and doesn't use the inverter function because it is not required when A.C. from the dock is already available. If you have a separate charger and separate inverter, it makes no sense to run the inverter when shore power is available and plugged in, but you could if you don't have the important switch that allows ONLY shorepower OR the inverter to provide the A.C. on board. Doing so would be dangerous without the switch because you'd burn out the inverter immediately. You cannot have two separate sources of A.C. feeding your A.C. main breaker at the same time. All the charger is doing is converting A.C. to D.C. to charge your bank(s). When you have separate I and C units it is CRITICAL to assure that the charger switch on the panel is OFF when you are running the inverter, because you would end up using the batteries to make A.C. from the inverter to charge the SAME batteries - not a good idea at all.

Please reread the link I provided in reply #2 on page one of this topic.