and then a (wiring) miracle happens...

Discussion in 'Power - Site Power/Batteries/Generators/Solar' started by minus1psi, Aug 4, 2018.

  1. minus1psi

    minus1psi Member

    45
    7
    Aug 31, 2017
    I am sure we can plug in at home too, at least with the top popped -- not sure what happens if plugged in with the top down.

    I'm not convinced that the WFCO will actually fully charge the battery as determined by checking its specific gravity with a hydrometer. Bulk mode only applies until a battery reaches a certain state of charge - maybe 80% to 90%. After that a three-stage charger goes into absorption mode to complete the charge, then into float mode to keep the battery charged. Typically battery manufacturers recommend that absorption mode be at something like 14.6Vdc. The WFCO 8725P uses 13.6Vdc. The best charge controllers are programmable to allow for different battery types (wet cell, AGM, lithium) and for slightly different charging parameters from manufacturer to manufacturer. I do not expect programmability from a 2010 OEM pop-up converter. That is the essence of my recent question. How do you ever get a full charge on your battery? It is one reason I am considering solar. I'm hoping that a good solar charge controller and enough sunny days between trips will allow the pup's battery to fully charge.

    Here is the latest version of the drawing. Thanks for all of the help. It is getting closer for sure.
    and then a wiring miracle happens 7.jpg


    I get the feeling that inverters are a religious issue here. Apparently I'm in the wrong camp for this forum [8]. That said my tendency is to arrange a system such that all of the 120v outlets can be powered by the inverter vs pulling the inverter out of the equation. Maybe we will try it and hate it, but that is closer to the arrangement we are after.

    I am tempted by the Victron Multiplus 12/3000/120 inverter-charger. As I understand it, all power sources are wired into that unit. It sits ahead of the converter - wired to batteries and shore power. The converter stays in place but doesn't have the as much management responsibility as before. The Multiplus sends power to the batteries when it is possible to do so. It adaptively draws from the batteries as needed, even pulling from both shore power and batteries at the same time if necessary (say you were tied into a 15amp circuit but needed more amperage for a period of time). The charger side is programmable, so it can be used for all types of batteries and tweaked to achieve the best charge. It is pricey at $1400 on Amazon for the unit with the 3000 watt inverter. I am not sure how much power it draws when not connected to shore power. I haven't seen one in real life or talked to an owner. You still need batteries and a battery monitor, solar panels and solar charge controller (if you want solar), numerous fuses, and disconnect switches. It adds up to a lot of money. It's hard to argue that it is cost effective for the amount of camping we do with the pop-up, but it sure sounds like sweet technology.

    victron_multiplus - 1.jpg
     
    Last edited: Aug 8, 2018
  2. McFlyfi

    McFlyfi Active Member

    239
    76
    Aug 1, 2014
    Thousand Oaks CA
    That is your answer.
    Either that or a real battery charger (true three stage with programmable parameters), probably won't find that at Wal Mart for 30 bucks though.
    I leave my 100w panel connected to the battery 24/7. I have a Trimetric SC2030 and a TM2030RV monitor, I know my battery is charged, and charged correctly per Trojan's specifications.
     
  3. minus1psi

    minus1psi Member

    45
    7
    Aug 31, 2017
    @McFlyfi Thanks. The SC2030 and TM2030RV are almost plan A... there is currently no other plan ahead of them. I would prefer to defer the solar components for a while. Do you recommend a battery charger? Would it installed in the pop-up? If so, where does it go relative to the WFCO converter?
     
  4. tombiasi

    tombiasi Well-Known Member

    4,531
    391
    Sep 1, 2012
    Northwestern New Jersey
    Bad choice I my opinion. If you have shore power you can have 30 or 50 amps. Do you realize how much current your batteries will need to produce to supply 3000 watts? About 250 amps + loss and efficiency make up. How long can that go on?
     
  5. minus1psi

    minus1psi Member

    45
    7
    Aug 31, 2017
    @tombiasi I agree that on a practical level the Victron Multiplus 12/3000/120 is not a strong candidate for us. I still like it though!
     
  6. McFlyfi

    McFlyfi Active Member

    239
    76
    Aug 1, 2014
    Thousand Oaks CA
    I don't have a battery charger at all (well, I've got a cheap $30 Black and Decker, but I wouldn't use it on my trailer unless an extreme emergency). Since I went solar, I haven't looked a battery charger at all. I imagine they're out there, but you're on the right track wanting to pump in your amps at 14.6+ volts.
    I've got the SC2030 on the 4 stage parameter, with the final "finish absorb charge" set to something like 16.2 volts.
    Read the manual for the SC2030 for a wealth of battery charging info that you can apply elsewhere.
     
  7. tombiasi

    tombiasi Well-Known Member

    4,531
    391
    Sep 1, 2012
    Northwestern New Jersey
    OK, you like it. I can understand that. I like the Gulfstream G500 but I don't see one in my future.:smiley:
     
    minus1psi likes this.
  8. emoney

    emoney Well-Known Member

    532
    257
    Jul 7, 2018
    I’ve had a Shumaker Smart Charger since my boating days and that thing has been great. Of course it’s a “stand alone type unit”, alligator clips etc., but that’s what I use at home. It was $70-ish from WalMart but it’s earned every penny. It can charge at 6v or 12v, has a conditioner in it along with a trickle or speed charge setting and does all 3 battery types.
     
  9. minus1psi

    minus1psi Member

    45
    7
    Aug 31, 2017
    @tombiasi I do think it could be made to work and for only a small fraction of a single percent of the cost of your upcoming private jet.

    Four lithium batteries plus solar panels along with various other bits of a system and you could pretty much live in it off-grid full-time, in the right locations. All of that for less than $10K. If we were planning to live in the pop-up I'd be all over researching 100% of the details and compromises. It tempts me in the following way. If we could justify the expense, we could take that entire system to a darkside unit in the future -- when we hope to travel more extensively and for longer periods of time.
     
  10. minus1psi

    minus1psi Member

    45
    7
    Aug 31, 2017
    @emoney Thanks for that info. I'll have a look.
     
  11. tombiasi

    tombiasi Well-Known Member

    4,531
    391
    Sep 1, 2012
    Northwestern New Jersey
    If I were to do this I probably wouldn't use a popup. Just ordered the G500. 13 month wait. I'll do a flyover at a rally.
     

Share This Page