Recent content by Martinjmpr

  1. Martinjmpr

    Troubleshooting Renogy DC-DC charger. Is there anything else I can try?

    OK folks (Especially Dave and Verkstad): THANK YOU! Problem has been identified (damaged wire on the negative battery cable.) Here is the underside view of the damaged negative cable (right at the terminal.) Pretty gnarly! So I cut off that end and crimped a ring terminal onto it...
  2. Martinjmpr

    Troubleshooting Renogy DC-DC charger. Is there anything else I can try?

    Dave: I have an extra Bojack fuse block (and extra fuses.) I can't think of any reason that WOULDN'T work. It would mean the circuit is fused on both the + and - sides but there's no down side to that, right?
  3. Martinjmpr

    Troubleshooting Renogy DC-DC charger. Is there anything else I can try?

    OK, I think I may have isolated the problem. I thought I'd try checking resistance to the whole cable from the battery to the cab. I'd been spending all my time looking at the + terminal (with the fuse.) But when I went to take the negative terminal off the battery, this is what I saw...
  4. Martinjmpr

    Troubleshooting Renogy DC-DC charger. Is there anything else I can try?

    So here's the update as of this mornings testing: I went out and connected the ring terminals at the fuse block to the same terminal (bypassing the fuse itself.) With the engine OFF it is showing 12+ v: So then I started the engine. Now showing 13+v and getting a strong green pilot...
  5. Martinjmpr

    Troubleshooting Renogy DC-DC charger. Is there anything else I can try?

    Thanks, that’s a good recommendation. I actually just changed out the fuse block a few months ago so that might be part of the problem. Sent from my iPhone using Tapatalk
  6. Martinjmpr

    Troubleshooting Renogy DC-DC charger. Is there anything else I can try?

    Posting here because this board is the fount of knowledge on power and electrical stuff as far I can tell. If you've seen my other posts you know that for the past 5 years I've been running my 12v fridge off of my "redneck Jackery" power box. The power box is simply a trolling motor box with...
  7. Martinjmpr

    DC-DC charger as an alternative to generator?

    UPDATE 6/5/2025: Field tested! We took a trip to Flaming Gorge in Utah last weekend. No electrical hookups at all and we were camped in a large group campground, essentially 'boondocking' but with reservations. As with our trip to Key West last year, I once again forgot to bring my external...
  8. Martinjmpr

    What component do I need to charge power station from a 12v source?

    Interesting, this is the system I use to charge the camper battery from the truck, using the truck as my "generator:" 1100W inverter attached to the truck battery and 120v AC charger plugged into the inverter. I tested it out in the field for the first time last weekend and it worked great...
  9. Martinjmpr

    What component do I need to charge power station from a 12v source?

    OK, that makes sense. Can the output of an MPPT controller be adjusted or modified? I assume if it is stepping down voltage from a 19v solar panel to the ~14 ish volts it would take to charge a LiFePo battery. But if I'm plugging it into a cigarette lighter-type adapter, which probably puts...
  10. Martinjmpr

    What component do I need to charge power station from a 12v source?

    So the Jackery/bluetti/goal zero etc must have something like that in it, right? Because they can be charged from a 12v socket. But it must be a small thing because those things aren't very big. That's the specific component I'm looking for. Yes, of course I can use a DC-DC charger. I...
  11. Martinjmpr

    What component do I need to charge power station from a 12v source?

    So the Bluetti, Jackery, etc portable power packs all incorporate a number of features with their LiFePo batteries. Since I like to make my own, I'm curious to know what exact component charges the battery? I presume it's some kind of DC-DC charger that is then connected to a step-down...
  12. Martinjmpr

    Switching my RVs house battery to a LifePO4

    I swapped both of the 12v lead acid batteries in our 2021 Rockwood Geo Pro 19BH last year so I may be able to speak to this. I was concerned about the on-board converter not being "rated" to charge lithium, but I can tell you after almost 6 months of experience (which included trips to the...
  13. Martinjmpr

    DC-DC charger as an alternative to generator?

    POSTSCRIPT: FOR THE FUSE COPS J/K. ;) I know safety is important and the last thing anybody wants is an electrical fire next to two lithium batteries and 2 propane tanks. :oops: First step was to fuse the big 2AWG cable running from the truck battery to the 175A Anderson connector. After...
  14. Martinjmpr

    DC-DC charger as an alternative to generator?

    I think what he was saying is that it was smart for me to wait until LiFePo prices went down before I started my journey. Yeah the charger apparently senses the battery type and adjusts voltage accordingly. I think it charges at 14.3 or 14.5v when hooked to a LiFePo battery. The display on...
  15. Martinjmpr

    DC-DC charger as an alternative to generator?

    Eh, I don't know that I see that as being necessary. I mean I COULD put a big 40A or 50A fuse block on it where it connects to the battery but why? I mean, I guess in theory the Anderson connector could break if I hit a bump and ground the positive to the trailer frame but I think that...
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