[Zoya]

A dealer in Annapolis wants $3,000 to install a Magnum 2000W charger/inverter plus $1,350 for a Xantrex Link 2000 battery monitor. So, $4,350 total, that looks a bit steep considering that the Magnum 2000 typically sells for $1,700 and the Xantrex Link 2000 battery monitor for a few hundreds. So my questions are:

-The boat already has a battery charger working with shore power, why would I need an power inverter with charging capability? Can I just get a inverter?

- Balmar Smartgage is only $350 and seems to be just what I need

Am I getting gouged?

Thanks.

 

[IStream]

Well, it seems steep to me by about $1K. If the Magnum install includes their ME-RC50 remote control panel (which it should, it's about $200), you can add single bank monitoring functionality to their system for another $200. See:
Battery Monitor Kit (ME-BMK) | Magnum Energy, Inc.

I've got a Magnum MSH3012 (MSH-M Series Inverter/Charger | Magnum Energy, Inc.) with the remote and battery monitor. The hardware cost me $2150 total at the boatshow and I put it in myself but depending on the complexity of your install, I could see it costing ~$1K to have a pro do the job. So I'd estimate somewhere in the low $3K range.

Yes, you could always add a separate battery monitor and inverter, but you won't save much on labor going this route and the integrated units are very convenient.

 

[Maine Sail]

A dealer in Annapolis wants $3,000 to install a Magnum 2000W charger/inverter plus $1,350 for a Xantrex Link 2000 battery monitor. So, $4,350 total, that looks a bit steep considering that the Magnum 2000 typically sells for $1,700 and the Xantrex Link 2000 battery monitor for a few hundreds. So my questions are:

-The boat already has a battery charger working with shore power, why would I need an power inverter with charging capability? Can I just get a inverter?

- Balmar Smartgage is only $350 and seems to be just what I need

Am I getting gouged?

Thanks.

The inverter install is well within the realm especially if it is an MS-2000 series with the ME-ARC remote.

The Link 2000 is way off the mark...? They have not made a Link 2000 in at at least 10 years...

Get the Magnum ME-BMK and this will work with either the ME-RC or the ME-ARC remote display..

 

[Zoya]

Thanks guys and so, what do I need a charger/inverter if the boat already has its own battery charging system?

Best.

 

[mitchbrown]

You don't need the charg/inverter if you already have a charger. In fact I work on boats for a living and prefer to see separate units as it makes problem diagnosis easier. A good 2000 watt inverter shouldn't cost you more than 500 dollars.

Also you don't really need the amp counting meter either as voltage is the best way to tell the charge state. A 12 volt battery should be 12.6 volts when full charged and should not be allowed to go below 12 volts. usually around 50% chg at 12 volts. these measurements should be with no load.

 

[IStream]

You don't *need* a combined unit but they are convenient, with automatic charging upon connection to an AC source, simpler wiring, integrated battery monitoring, etc. The troubleshooting advantage of having separate devices is true in theory but my experience in practice is that an inverter/charger is one of the most reliable devices you can put on a boat. Hell, I just pulled a perfectly good Heart Interface Freedom 2000 inverter/charger out after 20 years of yeoman service. The only reason I upgraded was for true sine power for some electronics I have that don't like the modified waveform, an AGM charging program, and the ability to use a small generator to augment inversion from the batteries if I choose.

If you're going to pay ~$2K to install a simple inverter and battery monitor to complement your existing charger, I'd argue that it's worth putting the extra ~$1K in to do it with an integrated inverter/charger. If your existing charger is nice, maybe you can sell it to defray the incremental cost of the inverter/charger. If your existing charger isn't worth anything on the used market, I'd argue you're probably gonna get a better charger going integrated.

 

[telecam]

Thanks for sharing your knowledge IStream. This is for a 2013 Beneteau which comes from factory with a good (I assume) battery charger and LCD monitor on the electrical panel so, that is why I was wondering why an inverter with a charging function was needed.

Thanks.

 

[IStream]

Also you don't really need the amp counting meter either as voltage is the best way to tell the charge state. A 12 volt battery should be 12.6 volts when full charged and should not be allowed to go below 12 volts. usually around 50% chg at 12 volts. these measurements should be with no load.

An unloaded lead acid battery falls to 12.0 volts at around 15% state of charge. If you get that low, you're doing damage. At 50% SOC, it'll sit around 12.5V. That means that you've got a dynamic range of only 0.1V from fully charged to maximum safe discharge, which requires a very accurate voltmeter if you want any kind of measurement resolution. In fact, the available voltage swing is even less than this because if the battery is cold, it's effective capacity drops so your calibration of voltage versus SOC is temperature-dependent. Add in the fact that it can be difficult to achieve an unloaded state every time you want/need to check the voltage, and you've got a much less robust method than by monitoring current via a shunt in the ground leg.

 

[mitchbrown]

Thanks for the correction. It seems I was off by a bit. According to the attached chart 12 volts is 30% charge and 12.2 is 50%. Although I was quite a bit closer than Istream.

a simple flip of the main breaker on the 12 volt panel is all that is required to unload the batteries.

It has been my experience that the amp counters are not in the least bit dependable. If I were going to use one (which I wouldn't ) I would still be using the voltage as the final decision maker when deciding on charge state.

I have never had a set of batteries last less than 8 years.

 

[mitchbrown]

One more thing. Since batteries from different manufacturers tend to have slightly different voltage/charge curves it is best to use a hydrometer to figure out when your batteries are at 50% charge and then see what the voltage is and use that as your lowest

 

[IStream]

Thanks for the correction. It seems I was off by a bit. According to the attached chart 12 volts is 30% charge and 12.2 is 50%. Although I was quite a bit closer than Istream.

a simple flip of the main breaker on the 12 volt panel is all that is required to unload the batteries.

It has been my experience that the amp counters are not in the least bit dependable. If I were going to use one (which I wouldn't ) I would still be using the voltage as the final decision maker when deciding on charge state.

I think you'll find that even a draw as low as C/100 will shift that curve quite a bit. Flipping the main breaker will kill most loads but if any of the 24 hour circuits that bypass the breaker are active, they can shift that curve enough to make a big difference.

If you had a bad experience with a shunt system I can understand your reluctance to use one, but in my experience they work well under real-world conditions. The only problems I've seen with the approach are due to poorly set parameters on the monitor (e.g. the known issues with the default parameters for the Xantrex Link monitors, see: Link-series Charging Algorithms -- The "Gotcha" Factor!).

 

[mitchbrown]

I think you'll find that even a draw as low as C/100 will shift that curve quite a bit. Flipping the main breaker will kill most loads but if any of the 24 hour circuits that bypass the breaker are active, they can shift that curve enough to make a big difference.

If you had a bad experience with a shunt system I can understand your reluctance to use one, but in my experience they work well under real-world conditions. The only problems I've seen with the approach are due to poorly set parameters on the monitor (e.g. the known issues with the default parameters for the Xantrex Link monitors, see: Link-series Charging Algorithms -- The "Gotcha" Factor!).

I don't want to be argumentative so this will be my last post. If there are loads other than bilge pumps you should really be thinking about changing the way things are wired.

And if there is a load it would make you think the batteries are lower than they really are. So you would charge them. no harm no foul.

For your information, I always try to convince people not to over complicate their boats. you can have the conveniences you want but there is a simple way of doing it. Although fixing all the supper complex junk that people have been put on their boats keeps guys like me working.

 

[IStream]

Ditto, I'm not trying to be argumentative. I don't doubt that what you're doing works for you and your boat. If you've got a clean wiring setup without a bunch of parasitic 24 hours loads (e.g. bilge pumps with solid state water sensors, stereo preset memory backup, etc., etc.) so you can get a true open circuit voltage measurement and you're not making your voltage measurements at different temperatures within the same discharge cycle, your method is totally valid.

I was just trying to make the point that the current sensing method works well too and is tolerant of a lot of wiring sins, temperature variation, battery styles, etc. and I wouldn't hesitate to recommend it as a workable, even preferable, solution without having access to the boat in question.

 

[mitiempo]

Here is a chart from Trojan showing SOC vs voltage as well as specific gravity.



Specific gravity should be checked seldom, only really necessary when equalizing batteries. It is a good way to introduce dirt and foreign material into the electrolyte which leads to the death of a battery. Voltage can be used for checking state of charge but requires a resting battery. After charging it can take 12 hours or more without load for the electrolyte to mix thoroughly for an accurate reading. A good battery monitor - Victron is one example - is the most accurate method of determining state of charge as long as it is calibrated properly when installed. It should be synchronized regularly when the batteries are known to be fully charged, for example when you have been on shorepower with a charger in use for example.