Off Grid / CPAP power pack build started.

Discussion in 'Camping for the Medically/Physically Challenged' started by dbhost, Mar 28, 2021.

  1. dbhost

    dbhost Well-Known Member

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    For those of you still tent camping, those with campers that don't have onboard batteries, and those that don't want to use their camper electrical system to power CPAP off grid. I have come up with a solution that I have finalized the design and have ordered the components that I don't already have in inventory. Here is the shopping list, and the process. I will be providing 2 USB Charging ports, 2 12V power ports, one switched, one constant hot, and a 95 amp / hr deep cycle battery.

    Harbor Freight Tailgator 900w peak 700w running generator. These are being clearanced right now at a good sum more than I paid for mine. I am not fully pleased with it so I am not going to link it. I paid less than $100.00. For that price it is worth it. It's 2 stroke requring oil / gas mixture, it isn't super fuel efficient, 5 hour run time at 50% load. I am hoping to be able to replace it with a 2KW AiPower SUA2000iV.

    Super Start RV / Marine Deep Cycle Group 27 battery. Would have preferred Duracell Ultra BCI Group 27M 12V 92AH Deep Cycle AGM battery.

    NOCO HM327BKS Group 27 battery box.

    ###### NOCO GENPRO10x1 10 amp onboard battery charger. This is a pending purchase waiting for budget.######

    Deyooxi Quick Charge 3.0 Cigarette Lighter Outlet, 3 in 1 Charger Socket Panel 12V/24V Dual USB Car Socket with
    LED Voltmeter for Marine Boat Motorcycle Truck Use.

    [email protected] Custom Accessories 48877 Lead Marine (1) Battery Terminal, 1 Pack.

    Ginsco 12v outlet socket marine weather sealed.

    HyperTough 3/4" x 60' Electrical tape. Local pickup at Walmart $0.57

    300 PCS Heat Shrink Wire Connectors Qibaok Insulated Electrical Terminals Kit Waterproof Marine Crimp Connector Assortment Ring Fork Spade Butt Splices.

    2 pack ATO / ATC inline fuse holders, waterproof.

    14 gauge x 25' stranded copper. Red, and Black. $8.00 each. Local pickup at Walmart. I used less than a foot of each to extend harnesses.

    NOCO NCP2 battery anti corrosion spray. $3.97 at the local Walmart.

    PROCEDURE:

    #1. Install battery to battery box.

    #2. Measure, mark, and drill mounting holes for Lighter outlet / charger socket / switch panel, physiclaly install.

    #3. Measure, mark, and drill mounting hole for second lighter socket. Install.

    #4. Size up length of wire to graft marine fuse holder in to replace lead to panel switch power in. Using head shrink butt splices splice together, Attach blade connector on one end, and appropriate ring connector on other end, crimp fully, and shrink heat shrink tubing.

    #5. Replace ground ring terminal with heat shrink tubing fitted proper size ring terminal. Shrink all heat shrink.

    #6. Create power lead with other marine fuse holder in second power outlet. Butt splice, ring connector, shrink heat shrink etc...

    #7. Create proper length ground lead for second power outlet to match length of first one. NOTE, these should be the same size as the 3 in 1 panels OE fitted wires.

    #8. Leaving approximately 7" including the fuse holders free, bundle all wires together and tape into a single wiring loom.

    #9. Tape ground wires together and tape power wires together so they are neat in the box.

    #10. Slide positive wire ring connectors over positive side battery bolt on stud. Run down wing nut to snug it down.

    #11. Slide negative wire ring connectors over negative side battery bolt on stud. Run down wing nut to snug it down.

    #12. Apply NOCO battery terminal anti corrosion pads and bolt on Marine battery end to both positive and negative terminals.

    ######NOTE Steps 13 through 16 are to be done when I get the onboard battery charger. I want the NOCO 10 amp 1 bank and it is more $$ than I have right now.######

    #13. Because I have a warped sense of humor, and this is unlucky #13. Unscrew terminal stud wing nuts remove wires, and remove battery.

    #14. Measure for, mark, drill mounting holes for, and install onboard battery charger to the side of the battery box, using stainless steel large diameter head panhead screws, with locknuts on the outside.

    #15. Reinstall battery, and wires where they were prior to step #13.

    #16. Route wires into box, and install positive charger lead ring to positive side marine battery end ring post. Negative to negative, tighten.

    #17. Apply NOCO battery corrosion protection spray on all exposed connections. This will keep the acidic fumes form eating up the connections / terminals etc...

    #18. Install correctly sized fuse for the circuit in the fuse holders. I am chosing to keep the protection conservative at 15 amps although some run 20 amp fuses in these types of circuits.

    #19. Test, test, test...

    Comments:

    I have used the single fused outlet with the battery during the ice storm in february to power my Z2 travel CPAP. I was without power for 4 days, nights 2-4 were run on the battery. On the day following night 4, I recharged the battery in a little under 2 hours charging time using my B&D bench top charger. Measured charge before recharging was still over 12.2v.

    Until such time as the onboard charger can be bought and installed, I am going to keep using the B&D, but it is NOT the configuration I want.

    Long term, I want to have the onboard charger on one side, and a solar charge controller on the other, so I can charge either from generator, or solar. If there is a combination charger that is mountable that does solar and AC to DC charging, please let me know! I would prefer a single device.

    The Oreilly battery obviously isn't the best, it is what was available in a panic when my Everstart 1100 amp power pack, failed to run the CPAP for more than an hour on the first night. This is NOT what I had experienced with it before and what pushed me to massively upsize the battery. I would prefer an AGM or lithium battery, It looks like Duracell has a similar deep cycle AGM group 27 for about $200.00, when this lead acid job dies, I will certainly replace it with that.
     
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  2. dbhost

    dbhost Well-Known Member

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    So according to my Fedex tracking, my battery box will be here tomorrow.

    The Deyooxi panel is wired up, the harness is more or less built.

    [​IMG]

    I used 2 ATO style marine safe fuse holders that have been living in my toolbox / supplies now for a little over 21 years now. I bought them for a project on my old Jeep before I ended up buying a new pickup instead.

    I still don't have the second marine grade 12V port, and do not have faith that the Deyooxi switch will handle 30 amps, so I am wanting a switch AND port / outlet. I don't mind, and can use the added USB charging ports, but I do not want, nor do I need a second voltometer. I am thinking about grabbing a second 3 in 1 panel with a similar layout to the Deyooxi but lacking the voltometer.

    I am still debating that. Not sure how much harm there is in having a second voltometer connected up... Seems kind of dumb and redundant to me...
     
  3. dbhost

    dbhost Well-Known Member

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    Okay so project done, so far.

    [​IMG]
    The power box in ready to use mode.

    [​IMG]
    The power box in charging mode, for now... This is why I want a proper built on and wired in place charger.

    I didn't get the hole center alignment on the middle hole for the left panel quite right, but it works. The devices are all gasketed so no need for sealant.

    Both sides work, but for some reason one side voltometer reads 12.7v and the other reads 12.8, while my multimeter reads 12.65. So the voltometers aren't exactly trustworthy. I need to test power output still, but seeing as I have voltage to the voltometer I believe I am good.

    The harness is spot on. A bit long but that gives me lots of slack to take the top off.

    It should be noted that I overspent on this project because it served as an excuse to stock up on my dwindling supplies of totally out ATO fuses, and crimp connectors with heat shrink. I bought electrical tape that I didn't really need as I have since found 4 rolls of previously unopened tape in a box in the garage.

    Looking at comparable commercially built items, I have twice the output ports, with about 25% more amp hours storage for if I cut out the cost of supplies I had on hand not what I showed above which assumed buying everything new, means I had about half the cost of commercial units with less capacity. The only thing I lack compared to commercial device is a tiny 300w inverter, and I chose to leave it off. I HAVE a 500w modified sine wave inverter that works, it just makes me nervous with the laptop.
     
    Last edited: Apr 3, 2021
  4. Arruba

    Arruba Well-Known Member Gold Supporting Member

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    This is a timely post as I been pondering building a portable power pack type thingy myself. Yours looks well done to me.

    Thanks for posting.
     
  5. dbhost

    dbhost Well-Known Member

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    Happy to help.
     
  6. OR_scott

    OR_scott New Member

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    I added solar to mine. I actually added solar to my pup and to my power generator/battery box. So much nicer than the sound of the generator. As long as you have sunlight. Some FS camping is pretty shaded I get that.
    Hope it works well and you have awesome camping! I can’t wait for a couple more weeks!
     
  7. Drufus

    Drufus Member

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    Nice work. I added external battery terminals as well so that i can hook up solar or other charger without opening the box. Thanks for posting your project.
     
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  8. NMroamer

    NMroamer Well-Known Member

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    FYI. A modified sine wave inverter normally takes a sawtooth sine wave and cuts off top at 70 percent, that is where the power is.
    It then delays the timing to make a square wave.
    Works better with most electronics that way.
     
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  9. dbhost

    dbhost Well-Known Member

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    How did you manage the external terminals?
     
  10. Drufus

    Drufus Member

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    upload_2021-5-7_8-10-37.jpeg
    here you can see the external terminals good for ring or clip connections.
     
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  11. dbhost

    dbhost Well-Known Member

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    My intent was to as cleanly as possible, route the cables from the inverter striaght up through the vents as they provide a pretty good amount of space for cabling... But this looks awesome as well.

    My Bigger issue is converting the 12V cigarette lighter plug input of the inverter, to ring terminals. Not sure how to identify which side is positive, which is negative...
     
  12. SteveP

    SteveP Well-Known Member Platinum Supporting Member

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    on the barrel plug the tip is positive and the side contacts are negative. You can also use your multimeter, probe the cut ends of the wires, If the voltage reading shows as positive the wire probed with the positive lead of the meter is your positive, if the reading shows as negative the wire probed with the positive lead is negative.

    Edit: That's not going to work unless the wire is powered, tip is positive, sides are negative.
     
    Last edited: May 7, 2021

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