"Overkill" Solar Setup and Battery Bank for Camper
- Thread starter tmckenna
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shavermcspud
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As the OP stated in his first post, he is aiming to run 4x SCC @12v each, so he could in effect run one controller to each battery from each bank of panels, combine 4x 12v batteries in series to a 48v bank, draw the small internal 12v loads from a single battery and span the 4x batteries for the 48v inverter. Providing the internal 12v loads aren't high the batteries wont go out of Ballance plus he will have an SCC per battery to keep each one charged.
John Frum
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yesbeat you to the drawing. Yes I know its a bit primitive but I'm at work right now so I just scribbled it really quick. So if I had 4 charge controllers the number of batteries doesnt affect their ability to charge evenly. If I wire everything in parallel to keep it 12v, the 4 solar chargers will charge any quantity of batteries evenly?
John Frum
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absolutely
busbars for both legs make things sane.
boondox
Chief Engineer, RedNeckTech Industries
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Can't say I have ever tried such a system but it seems too complicated for me, especially for a boondocking system. Just because it can work doesn't make it robust or a good idea. Too many points of failure for me and no real benefit.
Sorry I may not have be clear. I'd like to run 4 clusters of 4 panels. So a total of 16 panels.
I noticed that 400w (4 panels) was the most that renogy offered tied into one charge controller.
I wouldn't do anything at 48v. The power coming out of those charge controllers is 12v at up to 400w. I would wire those parallel to get charging of 12v at up to 1600watts. They would be charging multiple 12v lithium batteries which would also be wired in parallel to be approximately 400ah of 12v capacity. Then those batteries would be wired to a 12v 3000w inverter.
mapguy525
Solar Enthusiast
Again -the inverter you infer will need much larger cabling than 0 or 1 awg to avoid massive voltage drop.
There is no cutting corners on equipment installation -if the desired outcome is to use the 4k / 12v inverter and running AC. It will require more battery, very large cabling, and appropriate over current protection(OCP)(Fusing). That is -if you want a safe and reliable system.
Yes, I'm aware. That is exactly what my question is lol
mapguy525
Solar Enthusiast
Seems we are going around in a circle......
Unfortunately it does. Thats why I removed the AC from the equation. I got one question answered regarding the equal charging of multiple batteries. Now I'm just wondering where people would put fuses, and possibly isolators in the "circuit" that I drew above, and whether or not I should wire everything to a center Distribution Block or just keep wire runs separate.
boondox
Chief Engineer, RedNeckTech Industries
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Before you get too deep into design you really need to do your energy audit. There is no way to design a system without a firm handle on what you need. This will mkae sure that you get a system that meets your needs and doesn't spend more than you need to.
My system is designed off the number of panels I can fit on the roof. I want to have the maximum capabilities for what I can fit on the camper. The battery bank size would be partially "designed" to accept the charging current from the solar, and I'd like to be around 300-400ah just because. The Renogy 3000w inverter would also be overkill just so I don't ever overload it. Its all probably WAY overkill but again, I'd rather be safe than sorry.
boondox
Chief Engineer, RedNeckTech Industries
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But if you use math, you can KNOW the answer. If money is no object and you are OK with spending it without knowing if it will work for ya, carry on. An energy audit is simple and you may find for example that you need less than you thought. Or that you won't have enough. It may allow you to make decisions on equipment that you won't have to replace or upgrade. You may be able to put part of the system up and leave it easy to expand if needed. It could save you a lot of time, effort and money.
Forgetting about AC, I'd really only be using maybe a 50" TV, a handful of LED lights, charging phones, and maybe playing the speakers in the camper. Considering the TV is the only big chunk and a newer LED will pull approximately 100 watts. I imagine in most situations I'd be utilizing less than 200 watts at a time.
mapguy525
Solar Enthusiast
No math typically equals a system that doesn't perform to expectations. 3k inverter needs serious size and quality cabling to fully perform. Installing to "partially" perform without a derating program is a fire hazard -plain and simple.
I agree with @boondox regarding the need for an energy audit and a wish list of items to power to avoid excessive duplication and lack of performance.
Example 3k inverter wired with to small of cable is a fire hazard.
I agree with @boondox regarding the need for an energy audit and a wish list of items to power to avoid excessive duplication and lack of performance.
Example 3k inverter wired with to small of cable is a fire hazard.
I'm well aware of the requirements regarding powering a 3000 watt inverter, and I will take all the proper precautions to do this safely. My question is not about wire size but more about circuit configuration and placement of fuses and use of battery isolators (if needed).
