Inverter
- Thread starter Mike Lowthian
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If you have answers, please help by responding to the unanswered posts.
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psneeld
Guru
I concur with the have a second great battery charger.
Dual units seem to have a higher failure rate and being stuck with no inverter might be inconvenient, but no battery charger is very tough (unless you have solar and wind to sustain you).
Dual units seem to have a higher failure rate and being stuck with no inverter might be inconvenient, but no battery charger is very tough (unless you have solar and wind to sustain you).
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Cigatoo
Guru
I have checked all battery fluid levels and are all up to snuff. No signs of over charging.
FF
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Folks with big house batts may find splitting the bank during underway charging may be faster .
Using a 200+ amp alt for 1/2 the bank and a serious charger from the noisemaker might knock the charge time down , although the final 10%-15% will take a long time as usual.
Using a 200+ amp alt for 1/2 the bank and a serious charger from the noisemaker might knock the charge time down , although the final 10%-15% will take a long time as usual.
OP
OP
Mike Lowthian
Senior Member
Thanks all. I am proceeding with my project but just discovered a small wrinkle with my choice of inverters, the Magnum 2812. My local vendor points out that it has a built in battery charger. But I already have a separate charger and it works fine. Will having two chargers at the same time cause a problem? My vendor does not know for sure but thinks it may so I should consider a different inverter which does not have a built in charger? Would appreciate any advice.
JDCAVE
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...but of course assuming having a second charger doesn’t overload your shore power or genny. You will want to check on that. The Magnum 2812 has a 125 amp charger, which would cost about 10 amps AC, or about 1/3 of a 30 amp service.
Jim
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The 2812 charger is desirable for rapidly charging a house bank with about 130 amps available. What size is your existing charger? Use it for start batteries with a cross over switch to charge house bank if needed.
BobMc
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Nothing wrong with having two charging sources. If you're lucky you can run them both at the same time (our Magnum and Xantrex play nicely together and gives a total of about 200 plus amps). If not, just run one of them! Always nice to have a backup.
BruceK
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I`ve had alternators,batt charger,and solar, all operating simultaneously. Batts coped fine. I`d think there`d be confusion somewhere in the charging systems, but nothing seemed to go amiss.
Bay Pelican
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My experience is different. For 15 years I had two chargers with various combinations of Xantrex, Max-Pro, Victron and Magnum. If both chargers went to one bank one charger or the other sensed the output of the other and reduced output. My solution was to put a battery switch in between the two battery boxes of six six volt batteries each and split the one bank into two when charging.
psneeld
Guru
My experience with a Promariner charger and inverter is, they will both charge at full capacity if the batteries need it but one tapers off pretty quickly if not.
I can charge a 30 percent depleted battery bank back to 90 percent in a little over an hour. That for my 660 amp hr bank would be around 130A, and the inverter has 75A charger and the stand alone is 50A.
Pretty close
But they are same manufacturer and similar age which might be the trick.
I can charge a 30 percent depleted battery bank back to 90 percent in a little over an hour. That for my 660 amp hr bank would be around 130A, and the inverter has 75A charger and the stand alone is 50A.
Pretty close
But they are same manufacturer and similar age which might be the trick.
Two chargers can be made to work together quite well but not likely to do so right out of the box. Some are more user programmable than others. The two different sense wires can cause problems but not insurmountable and not unlike dealing with alternators and programmable regulators. Depending on charge acceptance rate of the battery bank, having more than .2C charger capacity might only be useful for 30 mins or so when depth of discharge is greater than 30 percent or so. You can always disable the charger on the new inverter but the magnum charger is very programmable as are the battery parameters. Once you set it up you might find you only use the old charger to boost the bulk phase of the charge cycle and then just turn it off and let the magnum handle everything else.
What was said in the previous three posts is all true. But that doesn't change the fact that you can have two chargers simultaneously connected to one battery bank and they will coexist with no harm done.
Just don't expect that the two will charge at their combined rated output for long. But two is always better than one for faster charging.
David
Just don't expect that the two will charge at their combined rated output for long. But two is always better than one for faster charging.
David
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I have a Magnum 2800w/100amp inverter/charger as well as a Charles 80amp charger. They do well together. My inverter has a 37% cut out and I have accidently ran my batteries down that far once. That 2nd charger really helped to bring things back up to normal. I have AGMs so the depth of discharge was not a terrible thing and their ability to accept a fast bulk charge is a good thing. The Magnum always ends up being the dominant/survivor once the other is not needed.
If you do decide to only use one, I would highly recommend the Magnum as it is likely a superior charger. While it is a 3 stage charger, it really has a 4th stage...which is OFF or IDLE. Over many years a steady float charge( or an improper one) can take life off of a battery(bank). The idle mode in the Magnum will periodically test the bank and if it needs a charge, it will apply it. If not, then it will go back to idle. I think Magnum has trademarked this mode as "Battery Saver". I have 5.5 year old AGMs and they haven't blinked yet.
If you do decide to only use one, I would highly recommend the Magnum as it is likely a superior charger. While it is a 3 stage charger, it really has a 4th stage...which is OFF or IDLE. Over many years a steady float charge( or an improper one) can take life off of a battery(bank). The idle mode in the Magnum will periodically test the bank and if it needs a charge, it will apply it. If not, then it will go back to idle. I think Magnum has trademarked this mode as "Battery Saver". I have 5.5 year old AGMs and they haven't blinked yet.
Delfin
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You can get them both to charge until the battery is full, but you have to set the bulk charge voltage to something higher than you might normally want. That keeps the one from dropping out prematurely. That works ok for LFP if like me, you disconnect charging sources altogether when the batteries are full and you never float them, but not so great for lead acid where long absorption times and float voltages are needed.
I just installed three Sterling 30amp chargers to supplement the 120 amp charger on the inverter (plug for forum vendor Compass Marine who were very helpful). I have them both set for bulk voltage of 28 vdc (24v system), so one drops off about 15 minutes before it might ideally. If I wanted to stop that, I'd set both for 28.4, but disconnect the charging when the acceptance rate <3% or so of the capacity of the bank, which would be around 28.2 volts.
Easting,
A combo charger/inverter has the problem that a failure can disable not only the inverter function, a non-critical function, but also the battery charging and maintaining function, which is critical.
In addition, some of these units may automatically change configuration when detecting AC power in the charger side and converse. For example, from an engineering point of view, it is not clear to me how this power switchover impacts dual powered refrigerators.
Lastly, as exhibited by the new-coming Trillium battery, Lithium Ion battery technology is becoming a reality in boating that most probably will require a new type of charger. It seems to me that one should be able to upgrade the battery charger without having to throw away the inverter.
This is just my opinion as a boater and electrical engineer.
FF
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"Lastly, as exhibited by the new-coming Trillium battery, Lithium Ion battery technology is becoming a reality in boating that most probably will require a new type of charger. It seems to me that one should be able to upgrade the battery charger without having to throw away the inverter."
IOTA smart chargers have interchangable modules that handle this desire.
IOTA smart chargers have interchangable modules that handle this desire.
I'm another Magnum 2812 user. Installed it over a year ago. With a single house bank of 220 usable amps, it worked fine for the great loop. For overnights without using the genny, there was plenty of power to run two fridges, minimal LED lighting. Micro a sandwich or lite duty dinner, Make coffee in the morning and heat up a cold cup in the micro, pull the anchor and start up the engine.
(however, for dinner, we often made dinner while still running to save power for later, using a crock pot or microwave.)
PS we could not run the stove, AC or grill off the inverter as they are 220v.
Overall, very happy with that simple set up. The eng and gen start batteries are separate, but can start the eng with the house if needed (switch).
And, absolutely, get a battery monitor, and set your inverter to shut down if voltages goes below 12.2v.
(however, for dinner, we often made dinner while still running to save power for later, using a crock pot or microwave.)
PS we could not run the stove, AC or grill off the inverter as they are 220v.
Overall, very happy with that simple set up. The eng and gen start batteries are separate, but can start the eng with the house if needed (switch).
And, absolutely, get a battery monitor, and set your inverter to shut down if voltages goes below 12.2v.
FF you make a good point:
"IOTA smart chargers have interchangeable modules that handle this desire."
However, IMHO this is equivalent to having two separate units with the drawback of being vendor-locked. If they were separate units, one could benefit from competition and technical improvements across vendors separately for each function, charging and inverting. By using the combo, one locks the vendor pool for inverters to the charger's vendor and vice versa, in this case IOTA. Good for the vendor to lock a captive-customer but not necessarily good for the customer!
I suppose that it is not a very critical concern for many. For me, it is just a matter of preference.
"IOTA smart chargers have interchangeable modules that handle this desire."
However, IMHO this is equivalent to having two separate units with the drawback of being vendor-locked. If they were separate units, one could benefit from competition and technical improvements across vendors separately for each function, charging and inverting. By using the combo, one locks the vendor pool for inverters to the charger's vendor and vice versa, in this case IOTA. Good for the vendor to lock a captive-customer but not necessarily good for the customer!
I suppose that it is not a very critical concern for many. For me, it is just a matter of preference.
FF
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Bestitis,,,"I suppose that it is not a very critical concern for many."
Right , most folks dont bother with their 120v charger till it dies.
Then they think about a new one, not much is repaired anymore.
While new different makeup batteries might still be learning how to be charged , and need changes in the charge system, most folks use wet lead acid batts have seen little changes in a century .
Nano tech is improving carbon batts , that should be 300% more powerful at the same size , but so far there a decade away.
Right , most folks dont bother with their 120v charger till it dies.
Then they think about a new one, not much is repaired anymore.
While new different makeup batteries might still be learning how to be charged , and need changes in the charge system, most folks use wet lead acid batts have seen little changes in a century .
Nano tech is improving carbon batts , that should be 300% more powerful at the same size , but so far there a decade away.
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