Inverter Batteries R.I.P.

You need to charge the bank with a 24 volt charger. If you cannot, break the battery bank apart and charge each battery with 12 volt chargers. Then load test each battery individually, if they all check out, then try to fire up the inverter. Chances are the inverter is bad and not the batteries.

This sounds like a screwed up installation to me. Have you walked through the manual in detail (and the Magnum manual has plenty of it). I owned a full Magnum system for over six years that got a ton of use, as we lived on moorings full time for months at a time, anchored out 50-100 nights a year, etc. Ms4024 inverter, BMK monitor, AGS auto generator start. Flawless.

Someone took a shortcut or created a short; get a real marine electrician to go through the whole thing, with the manuals, in detail. Magnum is very helpful, but it helps if they are talking with someone who can walk them through what's there step by step. Trying to solve it on an internet forum is fruitless.

Inverter Batteries

I have just installed the Magnum 2812 on my 420 Carver too. I also installed 6 L16 6 volt batteries as I have a 125 volt fridge on board. I installed the Vitron battery monitor to keep an eye on my battery status as well. Used the whole system for the first time last weekend ,when we anchored in our favorite bay and were on the hook for 4 days.
The system worked flawlessly! The Vitron told me the state of charge in the batteries as the inverter kept the fridge going all night long. My battery state of charge would drop by about 20% in about 12 hrs (which is only about 10% of the total battery charge).
I run the Genset for about an hour twice a day, to keep the batteries up and keep the hot water at a good temp for dishes and showers. The 2812 can charge my L16's charged back up to 100% by doing this.
I think that having a 2812 for 4- 6 volt batteries is a little big. The inverter would kill a set of 4 6 volts in no time.

Not sure what you mean by that last statement. The mere size of the inverter doesn't "kill" the batteries; the load and amp hours out does. And a properly set up inverter will never kill the batteries, it will turn itself off before that happens. I happily ran a MS4024 Magnum inverter on 4 high capacity L16's for years of full time cruising and living on moorings and at anchor. I just wanted to run all the refrigeration on board over night and during the day, with occasional draw from , davit, entertainment systems, computers, microwave oven, coffee maker and a few AC lights. Worked out
just dandy. FYI, "refrigeration" alone includes a full size home Sub Zero side by side with ice maker, a free standing Scottsman Ice maker, a Marvel 30 bottle or so wine cooler and an Avanti beverage cooler.

Curious why you got a Victron monitor; Magnum makes a real nice one, which I had, along with one of their auto generator starts, that integrates beautifully with their inverter network and remote control.

When we bought our boat it had a 2000 watt inverter powered by two 6 volt golf cart batt's. They worked for a while but were old so died. We switched to two 12 volt's in parallel instead which have powered our electronics, albeit not too much of a load at perhaps 500 watts at a time, for as much as 1 1/2 days although not continuously. The batt's are charged through the house bank on their own breaker; it's the way we bought it and seems to work fine. Only glitch is that we had to move the inverter out of the engine compartment after a surveyor advised that it was not marine grade. Just curious, what is the practical advantage of having 6 volts in serial rather than 12 volts in parallel ?

Hi,

You would need to look at the battery rating.

The 2 in series obviously gives you 12V where as the 12V in parallel give you double what a single 12V of that rating will give you.

Understood regarding the voltages, ser vs par etc, but what is the advantage of using 6 volt batt's over 12 volt which are readily more common and available? Are there generally more CCAs inherent in 6 volt or something like that?

Hi,

Golf Cart batteries are pretty heavy duty, the original installer might have had a Golf cart and some spare batteries which is how you ended up with that arrgt.

Golf cart batteries are good for deep discharges which is why they are used to power inverters.

Bob

I used to install inverters. I've put in about 40 of them. I've tried them all. 8d's, 12 volt beep cycle, and golf cart. The advantage of 6 over 12 volt is none. What makes the golf cart better is cost per amp hour. Nothing else comes close. I've never tried agm or gel because of the cost per amp hour. The golf cart will give you the most bang for the buck by far and last 6 to 8 years if taken care of.

I'm new to all of this, but...

What is the advantage to using an inverter? It seems like a HUGE expense and headache to keep from burning gas in the generator.

You forget the fact that two 6 volts are much easier to physically handle than a single 12 of the same capacity.

Two main advantages in my opinion.

1) It allows you to turn the generator off when small or no loads are present, which is better for the generator's health. Also, we anchor out and use moorings a lot, and I feel very uncomfortable leaving a generator going unattended while we are away from the boat.

2) It is silent. Depending on the boat, generators can be noisy, sometimes very noisy both inside and outside the boat.

I didn't find my system to be any kind of headache at all, quite the contrary.
The benefits of 1) and 2) above out weighed the expense of the system.

I will admit it was a very close call between adding an additional much smaller very quiet generator and adding the inverter system. The former would have had the advantage of powering an HVAC unit or two overnight, but would have been much more expensive and much more maintenance.

Hi,

Is your shore power a single cord or two?

I have 2 30 amp breakers serviced by 2 power cords. Most marinas I've been to have one 50 amp connection so I have a pig tail that splits the 50 amps into 2 power cords that service the boat. This is very common.

you may see different in your area but twin 30 amp is not uncommon. it all depends on how the load demands were calculated when the boat was designed. my 32 ft boat had twin 30's my carver 405 has twin 50 amp breakers. there is no one size is better or more common.
are you using a shore power adapter from a single 50amp 220 to 2 30's that are 110? or just 2 30 amp cords to 2 shore connectors on the dock?
the reason you cant connect the neutrals is the phases of ac power which is a sine wave (alternating current) . i dont know how your panels are laid out it sounds like you have 2. you cant run everything on the boat with an inverter and be practical about it anyway it would be simplier to set up the panel with the items you really want running on the inverter and forget about the other side. (tv/sat, microwave, galley receptacles , some receptacles in different areas salon or cabin) i'm sorry you are dependent on your installer for this but i hope you are learning and studying. having an inverter is not that in depth but knowing how your own boat is set up will make you much happier with it in the long run
also in my opinion (maybe i'm the only one)the auto start is not something i would want it sounds good but what happens if you leave a seacock shut and the gen starts up, what happens if your in the engine room checking gen or changing the oil on it and it starts up. what if you wanted to install or work on some ac circuit and you unplugged the boat and then all of a sudden the genset starts up? its just something else to forget turn auto start off when fiddling around on your boat.

my bad, should have reread what i wrote before i posted i knew where i was going but didnt get there in the end. phasing is for sure on the black or red "hot" not neutral legs