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Topic: Converter/charger/inverter question (Read 488 times) previous topic - next topic

Converter/charger/inverter question

My converter/charger has failed. It is a separate unit from my inverter and my inverter seems to be working like it should. I have a used Magnum 2000 watt inverter charger that was given to me a few years ago. My question is can I use this magnum just as a charger for the batteries? I'm not prepared to do a full-on conversion of inverter /charger. I've replaced both my house batteries and my starter batteries and just recently had to replace my alternator. I'm still plagued by dead batteries and low batteries and I'm in the process of testing them to see if they need replacing luckily they're still under warranty. As I said my main question is can I use this Magnum just as a battery charger and not as an inverter until I decide what exactly I'm going to do? We're trying to keep our 4th of July camping reservation and not have dead batteries when it's all over. TIA for any advice. :o
Michael & Roxene, Aussie the wonder dog & his daughter Luna the lunatic.
1993 Grand Villa Unihome 280 build #4203
36' 8.3 Cummins 300 hp- 2001 Chevrolet Tracker toad

Re: Converter/charger/inverter question

Reply #1 –
Mike,

What inverter only do you have? bran? model? and of most importance size in watts? That last question will tell you what size cabling you should have from house bank to it.

How far from the house battery bank to that location?

While I suspect you can use the Magnum as a charger only (no first hand experience with that model, but suspect it could be used as one) I would sure look at using it as intended-- replacing both bad converter and stand alone inverter.

What do you see as the negatives for doing that?
Brett Wolfe
EX: 1993 U240
Moderator, ForeForum 2001-
Moderator Diesel RV Club 2002-
Moderator, FMCA Forum 2009-2020
Chairman FMCA Technical Advisory Committee 2011-2020

Re: Converter/charger/inverter question

Reply #2 –
Mike probably has the Taytronix 1500 watt modified sine wave inverter - same as our coach originally had.

The Magnum, if it is pure sine, would be a definite step up in quality of delivered AC power from inverter, plus a very good battery charger.

Pretty sure the Magnum would have a separate switch for inverter and charger function.  Our MS2812 does.  If so, using as a battery charger only would not be a problem.


1993 U280 SE 40' WTBI, Build: 4359
C8.3 300hp, 6-Speed, Exhaust Brake
960 watts on the roof (6 x 160)
Sorento (or BOLT) on a Kar Kaddy SS
"Nature abhors a vacuum"

Re: Converter/charger/inverter question

Reply #3 –
Stated simply, unless there would be a lot of work in replacing both old components with the one new one in the original inverter's location, just do it!  Better charging algorithms and better inverter.
Brett Wolfe
EX: 1993 U240
Moderator, ForeForum 2001-
Moderator Diesel RV Club 2002-
Moderator, FMCA Forum 2009-2020
Chairman FMCA Technical Advisory Committee 2011-2020

Re: Converter/charger/inverter question

Reply #4 –
If you have the MS 2012 - like most inverter/chargers - when it senses 120 V is present on the input terminals it will transfer 120 V to the output terminals (just leave unused for now) and also go into charge mode to charge the batteries it is connected to. The MS 2012 is capable of charging at 100 amps. This may be more than your old charger, so you probably will need to adjust the charge current to match your old charger or increase the wire size. Just turn the inverter on when you have gen or shore power and off when unplugged and it should work fine as a charger for your upcoming trip until you can do a complete conversion.
Peter and Tammy Fleming
1991 U300 GV 40 - Sold, owned for 4 years
Downsized to Roadtrek Popular 210 class B

Re: Converter/charger/inverter question

Reply #5 –
Peter has given you the direct answer to your question.

The rest of us aim to have your electrical system upgraded at what should be minimal cost!
Brett Wolfe
EX: 1993 U240
Moderator, ForeForum 2001-
Moderator Diesel RV Club 2002-
Moderator, FMCA Forum 2009-2020
Chairman FMCA Technical Advisory Committee 2011-2020

Re: Converter/charger/inverter question

Reply #6 –
Chuck that's the inverter that I have as well but my charger is a separate component in the water bay, it is located next to my 12-volt fuse panel. I am not home at the moment to take pictures and record necessary information. Many at foretravel at the Grand Villa reunion last month said my charger was part of my inverter, but I don't think it is. I think it's connected but I think it's a separate entity. I'm struggling to rid the coach of all the Gremlins and replace what needs to be replaced as I can afford it. I can't express how grateful I am to the help you guys give the inexperienced people like myself, it is truly a blessing
Michael & Roxene, Aussie the wonder dog & his daughter Luna the lunatic.
1993 Grand Villa Unihome 280 build #4203
36' 8.3 Cummins 300 hp- 2001 Chevrolet Tracker toad

Re: Converter/charger/inverter question

Reply #7 –
Mike,

Other than the proper slow-burn fuse and perhaps upgrading wire from house bank to new inverter/charger location, can't see any other real $$$.  And, even if just using the new unit for charging, you will likely have to upgrade the wiring as it can push a lot more amps into the batteries (a very good thing if dry camping).
Brett Wolfe
EX: 1993 U240
Moderator, ForeForum 2001-
Moderator Diesel RV Club 2002-
Moderator, FMCA Forum 2009-2020
Chairman FMCA Technical Advisory Committee 2011-2020

Re: Converter/charger/inverter question

Reply #8 –
The existing converter/charger is wired directly to the 12-volt fuse panel which I can only assume is correct?? Trying to stay on the trail of what goes where and how everything works together
Michael & Roxene, Aussie the wonder dog & his daughter Luna the lunatic.
1993 Grand Villa Unihome 280 build #4203
36' 8.3 Cummins 300 hp- 2001 Chevrolet Tracker toad

Re: Converter/charger/inverter question

Reply #9 –
Quote from: mikerox –
The existing converter/charger is wired directly to the 12-volt fuse panel which I can only assume is correct?? Trying to stay on the trail of what goes where and how everything works together

No, that will not work with any high-amp charger, converter or inverter charger.

It will need to go directly to the house battery bank, preferably with a slow burn fuse if using the inverter function.

Normal location is "as near the house battery bank as possible, but not on the same compartment".

Same for the inverter you have now (hopefully) or any inverter/charger you install.

It would surprise me if yours wasn't already wired this way.
Brett Wolfe
EX: 1993 U240
Moderator, ForeForum 2001-
Moderator Diesel RV Club 2002-
Moderator, FMCA Forum 2009-2020
Chairman FMCA Technical Advisory Committee 2011-2020

Re: Converter/charger/inverter question

Reply #10 –
Brett, good to know, maybe that's been my problem all along, I am assuming that, when wired correctly, the converter/charger will charge both house and starter batteries? Where it is in the wet bay, it's in fairly close proximity to the house batteries. I'll post pictures when I get home, probably be late today or tomorrow
Michael & Roxene, Aussie the wonder dog & his daughter Luna the lunatic.
1993 Grand Villa Unihome 280 build #4203
36' 8.3 Cummins 300 hp- 2001 Chevrolet Tracker toad

Re: Converter/charger/inverter question

Reply #11 –
Quote from: mikerox –
The existing converter/charger is wired directly to the 12-volt fuse panel which I can only assume is correct??
I think Michael is referring to the main 12 volt BREAKER panel in the large center storage bay.  That IS how the original converter/charger in our coach was connected.  There are 3 large round 90 amp circuit breakers at the top of the panel.  The breaker at the top right corner (in photo below) was the connection point for the red positive cable from our OEM converter/charger.  It is a auto-reset breaker.  The ground cable from the charger went to the common ground lug on the panel.  The converter was plugged into the 110V duplex outlet above it on the wall.

See automotive Wiring Diagram B-2126 linked below (strangely...the linked diagram is a mirror image of my actual OEM paper copy).

https://www.foreforums.com/index.php?action=media;sa=item;in=3299#viewitem

The single stage 75 amp "battery boiler" charger/converter that came (along with TayTronics inverter) in our coach is shown in photo 1 & 2.

We initially replaced it with a much better 4 stage charger/converter shown in photo 3 & 4 (but retained the TayTronics inverter).

Our final upgrade was to remove the TayTronics inverter and the 4 stage charger/converter and replace both with the Magnum MS2812 inverter/charger mounted on the bay wall as shown in photo 5 & 6.  Moving the inverter from under the entry door steps to this location cut the length of connecting battery cables in half.  Original 3/0 inverter to battery cables were replaced with fresh 4/0 AWG.

Photo 7 shows the 12 volt breaker panel after our Magnum inverter was installed.  The big 175 amp fuse which originally powered the TayTronics inverter is no longer being used.  The new Magnum has a dedicated 400 amp class T fuse mounted near the coach batteries.  Also note the 90 amp round circuit breaker at the top right corner of panel is no longer being used since the old converter/charger is gone.

1993 U280 SE 40' WTBI, Build: 4359
C8.3 300hp, 6-Speed, Exhaust Brake
960 watts on the roof (6 x 160)
Sorento (or BOLT) on a Kar Kaddy SS
"Nature abhors a vacuum"

Re: Converter/charger/inverter question

Reply #12 –
Quote from: mikerox –
I am assuming that, when wired correctly, the converter/charger will charge both house and starter batteries?
That assumption would be incorrect.  As wired from the factory, the charger/converter was only connected to the coach (house) battery bank.  It did not provide a charge to the start battery bank.

With stock factory configuration, only two ways to charge the starting batteries:

1.  Run the big engine and let the alternator do the job through the battery isolator..

2.  Activate the charger/converter and then activate the BOOST switch which ties both battery banks physically together.

1993 U280 SE 40' WTBI, Build: 4359
C8.3 300hp, 6-Speed, Exhaust Brake
960 watts on the roof (6 x 160)
Sorento (or BOLT) on a Kar Kaddy SS
"Nature abhors a vacuum"

Re: Converter/charger/inverter question

Reply #13 –
Man, you guys are rock stars! Chuck you are correct somewhat, that is very similar to my converter but mine is in the wet bay and the 12 BREAKER panel is next to it in the same section that my water tank is in not in the large storage compartment. It seems odd that the location of this is not standard! This is all starting to make much more sense to me now thanks to you guys. My next hope is that the Magnum charger is functional as I've never used it or tried it. It was given to me when I bought a bus that I had planned to convert into an RV. The bus project never got off the ground and the Magnum has been sitting on a shelf in the garage for 5 years. Now that I understand it a little bit more I will dust it off and see if I can test it. Not enough words to express my appreciation. My first step is to get my warranty batteries replaced as I'm pretty sure they're fried. I got him at O'Reilly's I took him there yesterday they charged him up and said they were good but when I got them home they were already down to 11 volts. And those are just my starter batteries those 160 lb house batteries is a whole another ball of wax.
Michael & Roxene, Aussie the wonder dog & his daughter Luna the lunatic.
1993 Grand Villa Unihome 280 build #4203
36' 8.3 Cummins 300 hp- 2001 Chevrolet Tracker toad

Re: Converter/charger/inverter question

Reply #14 –
Your coach is a 36' and ours is a 40' which can make for some differences in the storage bay layout.





1993 U280 SE 40' WTBI, Build: 4359
C8.3 300hp, 6-Speed, Exhaust Brake
960 watts on the roof (6 x 160)
Sorento (or BOLT) on a Kar Kaddy SS
"Nature abhors a vacuum"

Re: Converter/charger/inverter question

Reply #15 –
Michael,

Having your OEM battery charger/converter connected to the 12 volt circuit breaker panel works fine, BUT If and when you do decide to install the Magnum inverter/charger, it should be connected directly to the coach (house) batteries with fresh high quality battery cables.  3/0 cable might be OK for a short run, but 4/0 would be better.  Keep the cables as short as possible.

I added another photo (#7) to Reply #11 (above).  It shows the changes made to the 12 volt circuit breaker panel as a result of removing the old converter/charger and installing the Magnum MS-2812.

If you don't have the original installation and owner's manual for the inverter, they are available online.  Just do a Google search using the inverter model number.  Using the full inverter and battery charger functions of the Magnum requires the correct installation of AC wiring and DC cables.  It is also recommended to use a battery temp sensor for best charging performance.  Depending on the capabilities of your Magnum, you may need to install a separate inverter AC panel, and perhaps a shunt on the negative battery cable.  If you aren't sure how to install the Magnum, seek professional assistance.

1993 U280 SE 40' WTBI, Build: 4359
C8.3 300hp, 6-Speed, Exhaust Brake
960 watts on the roof (6 x 160)
Sorento (or BOLT) on a Kar Kaddy SS
"Nature abhors a vacuum"