Question about WFCo 8955 Converter

In my RV, I recently installed a 2nd AGM battery bank (2-100 amp hours), 1500w inverter, 160w solar panel and Morningstar Sunsaver Duo controller to charge both the original 75ah flooded cell battery and the new battery banks.  

I had intended to use the original battery only as a backup; but I discovered the converter accepts power from the 2 separate banks.  As I intend the new bank to be my primary source, I'm wondering if the new bank will charge the old bank when hooked to the inverter even if I'm not connected to shore power or generator. In other words, will the converter treat the 3 batteries as being wired parallel? Actually, I prefer this not to happen although I'm not sure there would be any drawbacks if it did.  

Does anyone have any experience connecting 2 battery banks to the WFCo 8955? Thanks to all.  This is a very informative site.

Comments

  • Magellan44
    Magellan44 Registered Users Posts: 10 ✭✭
    Sorry, I said "hooked to the inverter" when I meant to say "hooked to the WFCo converter"
  • BB.
    BB. Super Moderators, Administrators Posts: 33,431 admin
    From the installation manual:

    http://wfcoelectronics.com/wp-content/uploads/2015/05/9-3-Installation-Manual.pdf

    I do not see any way it should be directly connected to two different battery banks (especially an AGM and flooded cell set of batteries--They have two different charging requirements). Connecting to the WFCo would just be connecting the two battery banks in parallel (together).

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • Magellan44
    Magellan44 Registered Users Posts: 10 ✭✭
    Hi, Bill.  The wiring diagram does not show two "ports". But on my converter there are 2 ports reading battery 1 and battery 2 and I believe the 2 screws indicated on both the positive and negative posts on the diagram denote this.  So what I've done for now is connect cables to each port but disconnect the positive cable at the flooded cell battery post.  That way, if I need it as backup, I can easily reconnect.  Both banks will be charged by my PV system in the meantime. This setup will avoid the parallel issue of 2 dissimilar battery banks you raised, but still give me easy access to the 12 volt system for my backup
  • scrubjaysnest
    scrubjaysnest Solar Expert Posts: 175 ✭✭✭
    My 8955 only has one input and output, what looks like a second input is actually a second set of posts tied to the input wired to the converter output. The WFCO 8955 converter is a pile of junk so your best bet is get rid of it and pick and install a converter with multi outputs for what you want. Seems I saw on the Iota site where they make a dual output converter.
    I also don't think you have enough solar for the 2 X 100Ah batteries, when I added a second battery I had to increase from 160 watts to 360 watts. With the cost of AGM's you will want to do everything to get max life from them.
  • Magellan44
    Magellan44 Registered Users Posts: 10 ✭✭
    scrubjaysnest: Thanks for your comments.  Prior to receiving your post I wrote to the company and got the following reply: John <j.klocek@wfcoelectronics.com> 
    • Apr 12 at 10:30 AM
    Message body
    When you are not connected to shore power the converter will not work. The converter needs AC voltage to operate.  Also all batteries connected to the converter have to be of the same manufacturer and type.

    Since that did not quite answer my question, I connected the flooded cell battery bank at the positive post of the battery.  The 12 volt system worked fine in the 2nd port.  I believe what you refer to as "second set of posts tied to the input wired to the converter output" is the middle of 3 sets of connections and indeed it's for the converter.  However, the bottom and top set of connections are for 2 separate banks. See http://wfcoelectronics.com/wp-content/uploads/2015/05/9-3-Installation-Manual.pdf 

    Your comments about the quality of the WFCo 8995 are echoed many times throughout the web.  However, my experience has been to the contrary.  It's been installed in my RV for 5 years.  During that time, we lived in the RV continuously for 9 months connected to shore power while house house hunting. The 8955 always performed well and maintained my cheap 75 ah battery which I installed 4 years ago after the original was stolen.  I still have that battery and it performs satisfactorily.
    Best regards
    Denis
  • Shadowcatcher
    Shadowcatcher Solar Expert Posts: 228 ✭✭✭
    One thing I have to remind my self every now and again, anecdotes are not data. There are a lot of WFCO converters out there and while we often hear of the ones that fail, how many are out there that are doing what they should.
  • 2manytoyz
    2manytoyz Solar Expert Posts: 373 ✭✭✭
    We custom ordered our camper, which was built to suit.  It came with a WFCO converter.  It appeared to work fine, but had some quirks.  The more lights on, the dimmer they'd become.  And when we went to bed, turned off all the lights, the converter had a high pitched whistle.  And after 2 years, the new battery was shot, despite being topped up with water, and the converter plugged in at our house.  It killed two more batteries before the converter itself died.  Turns out, my complaints echoed those I found online.  WFCO equipment is functional, but not great quality.

    I did like the breaker panel for the 120VAC equipment, and the fuse panel for the 12DC equipment.  Once I opened the case, I discovered the converter itself could be removed easily.









    The Iota charger was also rated at 55A, like the original, and fit nicely inside the WFCO housing.  I added the IQ4 smart charger module.  Now it doesn't matter what lights or 12V equipment is powered up, there's no noticeable change in voltage/light intensity.  My battery has lasted 4 years as it's not being overcharged.  Really good upgrade.

    I also have an Iota 75A charger connected to my solar battery bank.  It's performed well for the last 7 years, and maintains my 900AH battery bank when solar isn't available.


  • scrubjaysnest
    scrubjaysnest Solar Expert Posts: 175 ✭✭✭
    We just bought a new camper and it came with the 8955 like the one in the last camper. Like the previous one it will not go into bulk or boost mode of 14.4 volts. It's output is 13.6 volts or 13.2. spends most of it's time in float. I like the Iota mod and will most likely go that route this winter. We will be doing roof mounted solar in addition to the two portables I keep from the other camper. Will also upgrade the battery bank as this camper is a power hog compared to our last one.
  • Shadowcatcher
    Shadowcatcher Solar Expert Posts: 228 ✭✭✭
    Progressive Dynamics makes a replacement for the WFCO.