Minimalistic 12V setup with Solar charging - another solar question

Discussion in 'Camping Green' started by carguy37757, Jul 6, 2017.

  1. carguy37757

    carguy37757 Member

    Jan 13, 2013
    Hey all. I recently inherited an older Viking SP190 pop up. It needs some work and doesn't have really many features at all. No HVAC/heat, no fridge, no stove, no sink. Has a couple of lights and a few outlets.

    What I want to do is either replace my lights with LED bulbs or buy separate LED strips to be mounted inside for lighting, add a 12V plug or 2 to charge cell phones, be able to run a fan to keep air moving in the camper while sleeping, and power my CPAP once I get the 12V adaptor for it. Very minimalist by my standards.

    I'm hoping to be able to set this whole thing up to run off a battery or 2 with solar recharge capabilities. I do not intend to run any 120v accessories through this setup. Only what's in the paragraph above.

    Realistically, what should I be looking at to make this happen? Do I really need a high dollar setup to make this happen?

    Thanks in advance.
  2. JimmyM

    JimmyM Well-Known Member

    Jun 5, 2014
    Franklin, MA
    You can get by with a group 27 or 31 battery, a 100W solar panel and a cheap PWM charge controller. The next question is... How long do you want to do this for? And what are the consequences of running out of power?
    Converting existing lights to LED is easy.
  3. carguy37757

    carguy37757 Member

    Jan 13, 2013
    My longest stint probably would be no more than 5 days. The consequences of running out of power is really a dead phone or waking others with my snoring. So nothing major but I'd like to be able to make it 5 days, recharging with the panel as needed.
  4. JimmyM

    JimmyM Well-Known Member

    Jun 5, 2014
    Franklin, MA
    I'd go with as much battery as your tongue and budget will allow. Group 31 minimum.
    Do you know what your fans and CPAP machine's amp draw are? Those are the biggest consumers in your scenario. With those numbers you can do a better estimate of you usage and figure out what's needed.
  5. carguy37757

    carguy37757 Member

    Jan 13, 2013
    At this time I haven't bought any fans or lights to know how much current draw is. I do not know what the cpap draw is.
  6. JimmyM

    JimmyM Well-Known Member

    Jun 5, 2014
    Franklin, MA
    LED Lights almost don't even count. The draw like 0.1 A each. The fans draw around 1.2A for a little 6" one to 3.5-ish amps for an Endless Breeze on high.
    I have no idea what a CPAP machine draws.
  7. Arlyn Aronson

    Arlyn Aronson Active Member

    Jun 11, 2014
    Houghton MI
    Our camper came with interior lights but no battery to operate them off of. We tested them to make sure they worked and haven't used them since. Our camper is about 5yo now. We own a nice little 2000 Honda generator that I love and use at remote construction sites. Funny thing is we've never brought it along camping. Seems we do fine with those LED lights that we wear on our heads. Another one goes on the campers interior ceiling. In the fall, when its gets dark darn early we'll use an ancient Colman gas fired lantern we have. I'm a believer in the KISS system.. :)
    hometownhiker likes this.
  8. JimmyM

    JimmyM Well-Known Member

    Jun 5, 2014
    Franklin, MA
    But none of what you just posted addresses what the OP asked for.
    Can't run a CPAP on Coleman fuel. :D
    Garrity likes this.
  9. SteveP

    SteveP Well-Known Member

    May 21, 2015
    Too many variables to be able to give a decent answer about solar. Depending on where you camp it may do you no good at all. But I will say that you'll get the most bang for the buck by investing in batteries. Solar charging is worthless unless you have the battery capacity to hold and distribute the power. Two G31DCs or 2 GC2s might get you by five days, depending on the fan you use. The GC2s will give you more discharge/recharge cycles and hold up better long term, and they take up less space on the tongue but they're much more expensive. You can always recharge with jumper cables attached to the TV if necessary.
    emoney likes this.
  10. JimmyM

    JimmyM Well-Known Member

    Jun 5, 2014
    Franklin, MA
    GC2s are not more expensive. a pair of Sam's Club Duracell GC2s (Made by East Penn Deka) are $84 each. Even after core charges and tax I paid $217. A quick internet search shows a single G31DC is $160.
    2x GC2s = 215AH for $217
    2x G31DCs = 210AH for $320+tax+core charges

    It's not even close. Even if you chose Trojan GC2s (T105). They're only $150 each.

    Ultimately it all depends on how much power you use. You'll need to figure out what your stuff uses.
  11. p

    p Active Member

    Jun 9, 2014
    Jumper cable recharging is fictional. Sorry.
    theseus likes this.
  12. BirdsNest

    BirdsNest Active Member

    Jun 12, 2017
    You're not going to get a significant charge that way, unless you run the tow vehicle's engine and let it sit for quite a while, but it definitely can be used to get a bit of "emergency juice" into the trailer battery. It's also an option to temporarily run the trailer's electrical system (lift motor, for example) off of the tow vehicle's battery when the trailer's battery is dead.
  13. XKPin

    XKPin There's no situation so bad it can't be made worse

    Oct 28, 2016
    Gloucester, Virginia
    Looks like you have a good start for an 'all' DC system. My [2C] for my DC operation:
    --I do not use the alternating current system at all and have gutted it from my past and present pups. No (LOL!!!) - it doesn’t make me more of a man, just a personal preference [LOL]. As a hermit I prefer the periphery of uncrowded campgrounds and sites outside the norm.

    —My pup battery system was selected for these reasons because I am all about options:
    1. My pup battery exactly matches my TV battery for emergency exchange. Not as large as I could have purchased, but the internal resistance of each battery matches and is more efficient for a transfer of current from the TV should an emergency charging be necessitated.
    2. The pup battery is securely mounted in a marine box with a ratchet strap for easy removal and a quick disconnect for the PUP wiring. I have had the battery voltage drop to 12.0-VDC and took the battery to a service station for a 4-hour recharge while I continued on a day trip to see what sites there were to behold. [!] Do keep a digital volt meter with you![!]
    3. Since I use my campsite as a base camp, the pup’s battery can be readily exchanged with my TV for recharging when site seeing. Stuff is small today so I also pack a battery charger and inverter.
    4. Vehicle batteries are generally warranted for 5-years and many deep-cycle batteries are warranted for much less, not that that should be a problem if the popup battery is properly charging when not in use.

    —With the AC cabling removed I store repair equipment, 8-gage emergency TV battery to battery jumper cables, spare bulbs, gold pan, battery charger, inverter, etc. In this space I have also installed my own distribution panel (part# BLU-5026)(pic) with circuit protection for each load.
    —One interior light remains. Used when I misplace my headlamp or lighter. Otherwise I prefer natural lighting. I use $1.00 Walmart jar candles inside and a Tiki torch outside.
    —I installed automotive 12VDC outlets at each bunk for fans and/or cell charging.
    —I retained the water pump but seldom use unless the grandkids accompany me. I don't wash or cook inside to prevent odors from enticing raccoons or bears in my absence.
    —I have retained the smoke and Atwood alarm systems.
    —Refrigerator removed and replaced with two RevAShelf pullout draws and one fixed shelf installed for very practical storage (pic).

    Like most (all?) pups have separate electrical circuits for signaling versus domestic wiring. I installed my own domestic wiring and know every inch of it. Cost very little IF you know what you're doing!

    Now I’m not about self-abuse. . . I bring along my DeWalt drill with a few homemade attachments which raise & lower the tongue, set and retract the stability jacks and raise & lower the pup top. Needless to say, 12 VDC fans provide ‘cooling’ and Mr Heater warms when required.

    Most of my site selections are under old growth trees or under rainy skies [{}=], but someday I would like to buy a solar panel :)!


    Attached Files:

    Last edited: Jul 29, 2017
  14. penny

    penny Active Member

    Nov 9, 2017
    we carry a 100 w solar panel, a heavy gauge extension cord to connect the panel to the charge controller and two deep cycle sealed batteries. we keep the solar panel in the camper and freestanding, as we like to park in the shade, and with the extension cord, we can put the panel out in a sunny spot. In our small rv, we have a lot more running on 12 v than the pop up will have. we have not used this system with this pop up yet, and don't know if we will have to add a second battery for the pop up, but it's easy enough. You would also need an inverter, of course. The charge controller can be moved from camper to camper by just removing two screws, we kept it portable and have moved it from camper to camper as needed. we live in New Mexico, so most days are sunny, and we count on the sun to recharge the batteries.
  15. davido

    davido Active Member

    Jul 17, 2014
    With dual group-24 batteries I can get four nights in cool weather, running the furnace perhaps 1/3rd of the time at night. In warmer weather I can go a week or so without recharging.

    But even so, solar is a good idea because it reduces the need to budget carefully. A 100w panel can extend cool-weather camping a week or more, and warm weather camping indefinitely. A 160-200w panel could keep me going indefinitely in cool weather. Given I'm not retired, I am not prone to going on indefinitely-long camping trips anyway. :)
  16. ArkansasDon

    ArkansasDon Member

    Mar 7, 2018
    when I was building my trailer I wanted 100% off grid. No land line power (shore power) what so ever. I done a 6 months of research I on solar & went Renogy. I like their customer service, which had a positive impact on me choosing their product. I explained what I was doing for my trailer build & what equipment will be used @ certain times of the year & how long (hours during the day) along with giving them all the technical information as of amp. draw per hour. They came up with a fail safe system that will suit me for all 4 seasons. Battery I went with is VMax Tank 125 amp hour AGM with 10 to 12 yr life span, worth every dollar spent IMO.
    I have (2) Renogy 100 watt portable suite case style Monocrystalline solar panels, this way I can use 1 or 2 panels ran together when ever I need the extra power. Renogy 30amp Wanderer Charge Controller w\ battery temperature sensor. I have 20ft of 10 awg cable to stretch out & move my panel\panels where ever to follow the sun. I have 30amp fuse in between the panels & the charge controller to protect my system.
    I run Engel 22qt 12v. fridg\freez 24hrs on demand, Propex H2000 Heat Source tent heater on demand "seasonal fall, winter, early spring" use, Mighty Kool K2 12v. A\C "seasonal" only at sleeping hrs during summer months which runs continuously, 2 LED filtered green lights on the tent rack & the LED tent light strip in side the tent.
    I believe you get what you spend. Solar I feel you need to get the "best" energy efficient system you can afford. This goes for the battery\batteries being used with it.
    I do not trust China made solar panels or their components because these systems are NOT energy efficient from what I read. You will see how other will favor other manufactures.
    You want a system that will not undercharge your battery or batteries. This will cause shorter life span, once a battery is drops below 10v it is difficult to bring it back up to full charge. This is hard on the battery & it's life span. Another issue I was reading is excessive vibration from a inadequate faulty battery hold down without adequate shock absorption for the battery. This will weaken cells & shorten battery or batteries life span also.
    Lee's Alite and Popiworks like this.
  17. SpecialGreen

    SpecialGreen New Member

    Jul 5, 2018
    I just tried this, and it worked for me.
    Tow Vehicle: minivan with 135-amp alternator.
    Battery: 41.2 aHr Interstate HD24-DP 41.2 aHr
    • 12.89 volts at check-in and pop-up
    • 12.67 volts at lunch 1st full day (down 0.22 volts, or about 22%)
    • 12.5 volts at lunch 2nd full day (down 0.17 volts, or about 17%)
    • charged for 1 hour from tow vehicle with jumper cables.
    • = 12.71 volts after 1 hour of normal load (+0.21 volts)
    • 12.44 volts at lunch 3rd day (checkout). Still above 50% charge, yay!
    My charge level from 2nd day noon, to 3rd day noon (including the 1-hour charge session), dropped only 0.06 volts. So I'd say that with summer camping, we should be able to camp indefinitely with a daily lunchtime jumper-cable charging session of 60 to 90 minutes. (but we're not heavy power users)

    We have done an annual fall camping trip when temps are often around freezing ("MEA weekend" in Minnesota). This will be our first time in a heated Pup (instead of a tent), which we're really looking forward to. I plan to heat the Pup for an hour before bed, then a half hour in the morning (this will use a constant 3 amps). I think I may run the car engine for the hour before bed, and the half-hour after getting-up, while the heater is going full-tilt (maybe I should put Remote Start on the van, and a furnace switch I can hit from the bunk :) ). That would keep the heater fan load from depleting the battery at all, plus the 90 minutes of daily charging. Normally I wouldn't want the noise of an idling car in the morning, but at 32F, there are very few tent campers (just those "Zone 2B" campers from Biwabik)!
    Last edited: Aug 16, 2018
  18. Westcoast

    Westcoast New Member

    Oct 26, 2016
  19. Westcoast

    Westcoast New Member

    Oct 26, 2016
    Get a mister buddy
  20. Tyreguy

    Tyreguy Member

    Apr 8, 2012

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