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  1. chrisski

    22' travel trailer design

    Really think your battery wires are too small. 3000 volt amp inverter is actually 2400 continuous. If these batteries are run to a low SOC, the voltage will drop to as low as possibly 10 volts. THat’s 240 amps, plus another 15% for inverter losses for a around 276 amps. Wiring inverters for...
  2. chrisski

    Which BMS should I use?

    Overkill would have everything you’re asking for with the low temp and high temp cutoffs, but is limited to 120 amp output. 120 amps will run a 1000 watt inverter, except for perhaps some surge ratings. 80 -100 amps equals 1000 watts of power From an AC inverter. I have two of Overkill’s for...
  3. chrisski

    Anyone done any biz with this place for lithium's?

    I have not, but may be worth a message to the seller now to see if the USA, if that's where you're at, stock is still in. I ordered from a reputable vendor, who owned up to the shipping date on Ali being innacurate. The shipping date is for the much more expensive air freight. Ali will take...
  4. chrisski

    Which Crimp Connectors For Overkill BMS?

    I have took one of my spare busbars and drilled a hole in it, and used a tap and die set to make a hole for a screw. This method could be used to get an open end connector or other type of connector sized for a 26 AWG wire. I think most of us are having trouble because there is not a 1/4" to...
  5. chrisski

    Portable backup Solar battery charger voltage question

    Set right the charge controller will start charging before the BMS kicks in. THe BMS is for In Case of Emergency (ICE). Set the charge to the Battlborn spec sheet, absorption and float. If the BMS needs to be rest because of low voltage, look in the BB manual. THe reset may be automatic...
  6. chrisski

    Portable backup Solar battery charger voltage question

    So the excess voltage does not fry the batteries or trip the BMS. Not sure what happens when you over voltage a Lithium Cell, but when you put too much voltage in a Lead Acid Cell, the acids whether AGM, GEl, or FLA start to bubble. FOr FLA going a little high is the equalization (maintenance...
  7. chrisski

    Understanding requirements

    What I will add to what @MisterSandals said is depending on where you are, you’ll want to plan for some cloudy days, unless you have generator or grid backup. This can also give you some time to fix the solar charging if for some reason it stops charging. I’m finding my fixed system is...
  8. chrisski

    Electronic calculator?

    Not sure about an app, but in my signature block there is a online off-grid calculator. You can change the direction and tilt of the panel to see about outputs.
  9. chrisski

    Milk Crate First Try

    Recommend checking the 25 amp fuse. If that’s good, try hooking the SCC directly to the battery to see if it turns on. If the SCC turns on, the fuse or fuse block or wiring is bad. Most likely thing I see wrong is the wire from the SCC to the fuse block is not tightened down correctly or the...
  10. chrisski

    Cell Terminal Strain Relief, bus bars, and compression

    What thickness aluminum plate did you use, and can you give a link to the silicone mat?
  11. chrisski

    Building a solar powered way to sort/wash tons of rocks & gems

    Although 500 watts continuous would run it, doesn’t the inverter need to be significantly oversized to start it, like 2x to 10x? Kind of like the locked rotor amps on an Air Conditioner. A 50 gallon drum could weigh over 500 LBS filled.
  12. chrisski

    YES: RV Solar/ Li/ and AC running full time

    I like the idea of adding a second axle to a trailer to increase the weight rating, especially after seeing how limited I would be with weight ratings if a take the typical open trailer for sale and turn it into a enclosed RV. Same problem with the enclosed trailers: A 10k trailer is actually...
  13. chrisski

    Received new battery cells one is low

    Others smarter than me, but I would check that. I have two 25 ah batteries at 24 volts each. I’m working on two 24 volt 8S 280 ah battery packs with the first on the charger now. All my cells were delivered good, except one I physically damaged. That’s why I have the odd sized battery pack...
  14. chrisski

    24v milk crate

    I built one really similar to the one you linked, except at 24 volts: I did not install a power supply, so I just charge mine off the SCC. If wanted to recharge from 120 VAC, I would install the DROK powere...
  15. chrisski


    For my pass through Storage in my RV I added 12Volt/24 volt capable lighting to accommodate a 24 volt upgrade:
  16. chrisski

    Received new battery cells one is low

    I’m guessing this is for two 48 volt batteries. I could probably not skeep at night without testing the cell, and based off that would need to pass with flying colors, otherwise I would build the other batteries, and wait until the replacement cell came in. I would top balance and test...
  17. chrisski

    Need help on small solar system

    What does the specs say in the SCC? Sometime there is an over current limit for panels, or max amperage, or overpanel by XX% listed? Without that, I ovepanel my 15 amp 75 volt Victron SCC, which is MPPT. I put 600 watts of panels on it for a 24 volt setup which the SCC made maxes out at...
  18. chrisski

    Cell Terminal Strain Relief, bus bars, and compression

    @S Davis Do you considea these flexible as in the back and forth between the cell expansion and contraction, or is this bar flexible as in bending it into a C, but not so much in strain relief on the terminal?
  19. chrisski

    Cheap chinese wind turbine, an in depth exploration.

    I am Out of my league on that one. Not enough engineering classes. I’m not sure if your Amazon has it our not, but this book: "A Wind Turbine Recipe Book." has a peek inside to see if its worth the cost or not. It the book I took the links from. It tells you perfectly how to build a...
  20. chrisski

    Battery Advice

    If you see yourself doing not much different with your system, then why not swap out with new L16s. If you want a deeper discharge rate or a higher charge rate, then maybe Lithium would work. I’m swapping to Lithium’s now building my own battRey out of cells, and its more work than I thought...
  21. chrisski

    Solar powered air conditioner

    But the AC only takes 4.8 amps and two 100watt panels can make 13 amps?
  22. chrisski

    Cheap chinese wind turbine, an in depth exploration.

    I bought on Kindle for $5 "A Wind Turbine Recipe Book." You may be able to get some testing and figure out what to purchase next. This is an excerpt that has some illustrations about three phase AC, the coils, and briefly what a rectifier does. I would not just buy 6 diodes and connect...
  23. chrisski

    MPPT Wiring question

    Do not need to use the load output at all, but could for lower amp things. I would take the one labeled battery and hook it up to a busbar to distribute the power elsewhere. Here is one of mine: If you are only using this to charge your battery with no AC Inverter, hooking to the battery...
  24. chrisski

    Can you get a 48 volt battery from 24 cells?

    You could be brave and make a 36 volt pack with 12 S. I bet as much of a difference as it is in 48 volt parts are harder to find than 24 volt parts, I bet 36 volt parts are so much harder to find. I have seen a 36 volt AC to DC converter, but don’t ever recall seeing a 36 volt inverter.
  25. chrisski

    Building a solar powered way to sort/wash tons of rocks & gems

    I have done some small gold mining. Never worked out for me as in a living. I can only think that you could look in a magazine like the ICMJ Prospecting and Mining Journal, which has a classified section, check that section and figure the specs. I can guarantee that any equipment you’re...
  26. chrisski

    Can you get a 48 volt battery from 24 cells?

    I see no other way than buying 8 more like cells and putting them in a second pack. Although I have done this with a small lithium battery, Don’t like this idea. I did buy two different batches of Topband 25 ah cells and mixed three cells tested at 24.6 ah with blue shrinks wrap with five...
  27. chrisski

    Which Combiner box?

    With Y Cables, the MC4 connection will limit it to 30 amps, but the volts I’m not sure about. WIth 3S in a 250 watt panel, I suspect you could reach 100 volts. The specs for the Y cable would say max voltage. I’ve noticed panels are not often desifned to produce more than 10 amps, at that...
  28. chrisski

    Which Combiner box?

    You can read the specs for the Y cables. I use those so much easier to setup. I only have 2P, but I fuse each string. I also have the midnight solar combiner box for 3S2P with 600 watts total. Its mode for so much more than 600 watts. I also made a combiner box for half the price of the...
  29. chrisski

    Is putting PV panels inside a dumb idea?

    I tried a solar panel inside a non-tinted window and lost 66% of production. Each window is different. THe more UV light filtered, the less the output. Filtering out UV light is invisible to us.
  30. chrisski

    Converting from a lead-acid system to LiFePo

    Even with the lithium setting on a SCC you need to be careful. I charge mine at 13.8 absorption. Much higher voltage than that can wear on cells. I’ve seen SCCs with 14.3 lithium settings and I think that’s way to high.
  31. chrisski

    Cool Boondocker class C RV

    With the way you have the panel installed, seems like it will hold up real good. Even closed, seems like would provide a decent amount of wattage every day with it parked to the south. How did you secure that to the trailer. That is something I don't know about. I was watching some shows and...
  32. chrisski

    Cool Boondocker class C RV

    I’d like to see the idea for the awning like panel. The ones I’ve seen like PVC pipes that hold panels over a window don’t look good for the nightly winds I’ve seen in most place.
  33. chrisski

    Prebuilt LifePO4 - series or parallel ?

    I misread what you said, so I am changing to parallel. If the batteries are physically the same size, putting them in parallel is a better idea if wired correctly. In my signature block, there’s a document on paralleling batteries with math that says why some ways are better than others...
  34. chrisski

    Prebuilt LifePO4 - series or parallel ?

    The only that would stop me from putting them in series would be if they are not rated for it. There was one 12 volt battery I looked at that could only go up tp 48 volts. I think I remember others that could not go that high. The MOSFETS in the BMS need to be able to handle the voltage or...
  35. chrisski

    24 volt to 12 volt battery charging method?

    How do you get 250 amps? My two axle fifth wheel has 50 amps measured on a battery monitor when I raise and lower it. I am installing the Orion 24 volt to 12 volt 70 amp converter for the leveling jacks. If there is some surge which causes the jacks to act odd that the battery monitor can’t...