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  • #16
    If your inverter (or future inverter) uses 24V input, it would give you more ways to eliminate parallel connections, and have other benefits like reduced battery to inverter losses cable (for same size cable). But you'd lose the 12V power capability for small devices or starting the car. What Mike's telling you is that batteries in parallel arrangements aren't likely to live a long life because they will charge and discharge unequally. I made some charge current measurements of some batteries carefully wired in parallel (equal length cables, professionally terminated, etc.) at a new solar installation about a year or two ago during mid-day charging, and I saw a huge variation in the current the batteries were accepting, IIRC it ranged from 1.5A to 2.5A between. This means that if the batteries aren't completely recharged each day (or two), some will be "walked down" to really low SOC and eventually reach their end of life well before the others, who will soon follow because they are then taking up the slack. Your batteries are likely to have much more variation with imperfect cabling.

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    • #17
      Got ya. Thanks sdold.

      it sounds like parallel could work 50/50 for me. The batteries will always be charging, solar panels will be out all day while im working (at least 8 hours). The 900w 2 stroke genset i would probably fire 2x a week for top off.

      cabling i have the ability to do, and can get hands on professional crimp tools. That part doesnt scare me. Im more assembly oriented than i am design/math oriented (auto tech backround)

      ​​​​​​24v series with odyssey batteries look to be the way to go though, just for simplicity sake. If necessary i can always disconnect a terminal from one bank and use a battery to jump the car in a real emergency. For now the 1.5a solar trickle charger on the roof all day long is helping when im not using power. The whole idea of a separate battery bank is to not have to use the car for power, save fuel for driving

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      • #18
        As to any heater you were thinking of I would strongly suggest eliminating that plan if it involves solar power. There's not enough space on/in your vehicle for solar panels and batteries sufficient enough to use for heating. Have you ever seen the Mr. Heater line of portable heaters? Been using them for years. They really work well.
        2.2kw Suntech mono, Classic 200, NEW Trace SW4024

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        • #19
          I was eyeballing something like this for heat:

          https://m.harborfreight.com/12v-auto...ght-60525.html

          i dont expect much out of it, its really only to take the nip out of the air just in case. Where im going in CO they say to plan for worst case scenario a blizzard and down to -40F into April. Unlikely but possible. I have part of and plan to complete the rest of my ECWS sleep system and multiple quilts/long underwear to get by with.

          Mr Heater isnt really an option in this case since they are propane operated and i don't have enough open space in the car to give adequate clearance around the catalyst. And sleeping with windows down/sunroof open in extreme cold/blizzard conditions is pretty much a no no lol

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          • #20
            Originally posted by WanderWagen View Post
            I was eyeballing something like this for heat:

            https://m.harborfreight.com/12v-auto...ght-60525.html .
            Only: $14.99

            and you battery will last about 5 minutes. Get a jacket
            Powerfab top of pole PV mount (2) | Listeroid 6/1 w/st5 gen head | XW6048 inverter/chgr | Iota 48V/15A charger | Morningstar 60A MPPT | 48V, 800A NiFe Battery (in series)| 15, Evergreen 205w "12V" PV array on pole | Midnight ePanel | Grundfos 10 SO5-9 with 3 wire Franklin Electric motor (1/2hp 240V 1ph ) on a timer for 3 hr noontime run - Runs off PV ||
            || Midnight Classic 200 | 10, Evergreen 200w in a 160VOC array ||
            || VEC1093 12V Charger | Maha C401 aa/aaa Charger | SureSine | Sunsaver MPPT 15A

            solar: http://tinyurl.com/LMR-Solar
            gen: http://tinyurl.com/LMR-Lister

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            • #21
              Thats great and all Mike, i have a jacket and base layers. This is more for backup purposes...let's add the math to this and add it in the mix with laptop/phone at 810wh

              12v @ 13a = 156wh. Added to the 810wh i am theoretically capable of pulling a total of 976wh. Pretty sure with the proper battery bank i can get a bit more than 5 min on battery with it on the proposed 1kwh bank, not running the laptop or phone while this is running, its around 6 hours total i could use this for. More than enough to heat the ~75 ft^3 cabin of the car for an hour or 2 to get the blood flowing lol
              Last edited by WanderWagen; 03-17-2019, 08:24 PM.

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              • #22
                • 15 amp inline blade fuse
                Lets assume it pulls 10A @ 12V =120W Not nearly as much as I thought a car heater/defroster would. Will a pair of 60W incandescent light bulbs keep you warm enough?

                you know your battery size, and the loads, and the math. I'm just naturally skeptical , glass wrong size kind of guy.






                Powerfab top of pole PV mount (2) | Listeroid 6/1 w/st5 gen head | XW6048 inverter/chgr | Iota 48V/15A charger | Morningstar 60A MPPT | 48V, 800A NiFe Battery (in series)| 15, Evergreen 205w "12V" PV array on pole | Midnight ePanel | Grundfos 10 SO5-9 with 3 wire Franklin Electric motor (1/2hp 240V 1ph ) on a timer for 3 hr noontime run - Runs off PV ||
                || Midnight Classic 200 | 10, Evergreen 200w in a 160VOC array ||
                || VEC1093 12V Charger | Maha C401 aa/aaa Charger | SureSine | Sunsaver MPPT 15A

                solar: http://tinyurl.com/LMR-Solar
                gen: http://tinyurl.com/LMR-Lister

                Comment


                • #23
                  I understand lol. Not trying to come off harsh here. Frankly i dont expect much more than air movement out of it, for any significant heat production id have to get a real 120v ceramic heater and run it thru an inverter. Which almost triples the cost of my power bank (est.). I suppose 2 60w bulbs could do it, provided they are reptile tank bulbs...

                  the other option is heated 12v blankets above and below the bedding with auto shutoff defeated/extended timers. Or some sort of heated mattress pad. My current setup has gotten me down to single digits (2 quilts on top, base and mid layer gear with wool socks, surplus MSS patrol mummy bag and 6" memory foam), albeit a chilly night sleep in 2 shifts of vehicle heat. Insulating the windows will be more effective.

                  glass wrong size ha! I like that

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