Converter Charging Bypass

[DDRdan]

I have a 2002 19 Lite. I've added three 100ah Li-Ion batteries. I've also added a 370W solar system. I don't trust my converter to integrate it's 12v charger into that system. After the cost of the solar & batteries I'd rather not invest in a new converter too at this time.


It's a series 6300A MagneTek



1. Is there a way to stop the converter charge circuit yet use the existing converter for a 12VDC "in" connection?


2. Will I need to isolate the 'new' 12V external charging system "in" lines so they don't feed power to the converter?



3. Will I still be able to use the converter to provide 12VDC when on AC power?


I don't mind having to use a few breaker switches to turn things on and off to use the system in different configurations. It doesn't need to be automatic.



Thanks,
Dan

[kjlarson]

I had the same issue after installing larger batteries. I only wanted the converter to come on when connected to shore power to provide 12Vdc in the power center to power the 12Vdc circuits and charge the batteries. To accomplish that I disconnected the converter from the circuit breaker in the power center and connected it to the 120Vac hot wire from the shore power plug; don't forget to install an inline fuse to replace the protection provided by the circuit breaker. I don't have solar so still needed to charge the batteries from shore power, this solution was simple and worked just fine.

Now, given that you have the solar charging your batteries you don't want the converter, which may have a built in charger, trying to charge the batteries when connected to shore power at the same time the solar is doing that job, so you will need to isolate the converter charger function. You will have to do this in the power center.

As I am sure you are aware, the converter is changing the 120Vac shore power to 12Vdc; the 12Vdc output has two functions: #1 power the 12Vdc circuits in the trailer and #2 charge the batteries. This separation of functions is handled in the power center. You will want to preserve the #1 function and prevent the #2 function. You will need to research the wiring in the power center to discover which wiring needs to be removed to prevent the converter output from trying to charge the batteries.

Hope this helps.

[leisuresolar@gmail.com]

Depending on which Li batteries you bought, the old Magnatek will not harm them. However, it won't do a good, speedy job of charging either. There is a drop in replacement for Magnatek converters that is really easy to do.
https://bestconverter.3dcartstores.c...llax_c_64.html

Be sure to buy it from BestConverter.com, because the stuff from Amazon is not warranteed.

[DDRdan]

Originally Posted by kjlarson

Now, given that you have the solar charging your batteries you don't want the converter, which may have a built in charger, trying to charge the batteries when connected to shore power at the same time the solar is doing that job, so you will need to isolate the converter charger function. You will have to do this in the power center.

As I am sure you are aware, the converter is changing the 120Vac shore power to 12Vdc; the 12Vdc output has two functions: #1 power the 12Vdc circuits in the trailer and #2 charge the batteries. This separation of functions is handled in the power center. You will want to preserve the #1 function and prevent the #2 function. You will need to research the wiring in the power center to discover which wiring needs to be removed to prevent the converter output from trying to charge the batteries.

Hope this helps.

Thanks!


Found a schematic on the Magnetek 6332. It's pretty basic and from my preliminary review I'm just going to clip the battery charge circuit on the board and wire the battery bank into the 12V fuse board. Adding a breaker and large diode inline to prevent anything going back to the batteries.

(In case anyone else needs that schematic and diagnostic info: http://www.hayseed.net/~jpk5lad/RV%2...%20Binder1.pdf)

[persistent]

Generally speaking, connecting multiple converter/chargers to the same battery bank work OK together. So, leaving the Magnetek in place will probably work fine. However, it is an old design and has many possible failure modes. Replacing it with a new one designed for lithium battery charging would greatly reduce the risk that it would fail or that it would damage other things.

The lithium battery manufacturer may have advice worth listening too. Battle Born has tested many converter/chargers with their batteries.

I looked at schematics for the 6300A chargers. How they are configured varies a lot depending on year of mfg and individual model number. The charging function can be disabled for each one. Probably disconnecting the red wire from the control board will do the trick. However, there are variations and complex circuits that may be affected. If I am wrong, I promise to give you double your money back.

The battery - converter function is switched by a relay. You must maintain that function for the battery to supply house current to the fuse distribution panel when converter is not powered.

I see some models have a filtered and an unfiltered output. The filtered side remains connected to the battery for filtering and the other side supplies "noisy" 12 volt output. Using the lithium batteries for the filtering effect may cause problems due to interactions with the controllers built into the lithium's. The noisy side may not work well with some 12 volt appliances. If it were my rig, I would simply replace it with one recommended by the battery manufacturer.

Disconnecting the red wire may disable filtering and may disable all the filtered 12 volt branch circuits. I was not willing to follow down all the different models schematics.

Good luck and happy trails ahead!

[DDRdan]

Thanks to all for the info!

My batteries have built in Lin communication ports and a battery management system. My solar controller and my 120v charger can be monitored with the BMS data to give me on screen preferences and monitor the settings.

Been looking at new converters and none can assure me that there wont be a conflict with that type of system. I wish someone would make a stand alone converter and not include charging? The "all in one" concept just complicates things when introducing emerging battery technogy to an RV's electrical system.

I metered the entire board and found a way to diconnect the charge circuit, maintain the converters 12vdc relay, and install another relay in the battery line. It took a large relay with a heat sink to accomplish the change.

The converter's 12vdc will energize the new relay to disconnect the battery when plugged into120vac. And open the circuit when unplugged from 120vac

[kjlarson]

AIMs and GoPower both make stand-alone inverters and controllers. Check them out.