WFCO 55 amp converter operation

samandtheduck wrote:
I have had issues with bad connections and bad batteries in my motorhome and have them all resolved except knowing how this converter should work. It charges a new set of batteries to about 13.6V with no load. When I put a load (2 fantastic fans and a 12V TV) on the batteries the voltage slowly drops to about 12.65V and seems to stay there. If I shut the converter off it drops even further so it is doing something. When the load is shut off it takes about 20 mins for the voltage to get to 13.4V. I think over a longer period it will get to 13.6V. I have a friend who has a progressive dynamics converter and he says when he puts a load on the batteries the voltage drops from 13.3V to 13.2V and never goes lower. Do I have a bad converter or does this type just act like a trickle charger?

From my experience with the WFCO's

If your battery voltage drops (as measured at the battery) to 12.65 VDC when the power converter is running, from what I have seen, your converter is bad. With the converter plugged in and connected to the battery, the WFCO should be in float mode (13.25 volts), standard charge (13.65 volts) or boost (14.4 volts) It will switch between those 3 modes pending how drawn down the battery is. Anything down into 12 VDC range, the converter is not working right unless maybe you are over the 55 amp power rating. Which in this case does not sound like you are.

12.7 VDC with the battery at rest (left idle for 8 hours etc) and no loads on the battery, is 100% state of charge for the battery. Your 12.65 volt is the battery at full charge for all practical purposes. The converter is not lifting the voltage up where it should be.

Make sure you do not have some fuse etc between the battery and the converter blown etc, if the volts go back up from 12.65 to 13 plus with no load, then there are no blown fuses etc, just the converter is not working right.

If you have a WFCO 8955 converter, Progressive Dynamics makes a drop in converter that will tie into the existing DC fuses etc of the WFCO
https://www.progressivedyn.com/pd4600-converter/

If you go to Best Converter dot com, they sell the PD converter tweaked for that company to not need the metal case and it have the plastic clips to hold the converter in place. If you get the Wildkat PD 4655L it has the ability to jumper switch to a future lithium battery if you are on lead acid now. https://www.bestconverter.com/4600-series-Upgrade-Kits_c_133.html

They also offer the Wildkat PD 4655 MBA which is for lead acid and not able to upgrade later.


Call Best Converter and ask for Randy. He knows his stuff and I have always had positive outcomes dealing with his company. They are an authorized PD dealer. Some on Amazon are not and those off shore clones will not be warranted.

Hope this helps

John