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    Tail current charge table

    Eric Bretscher wrote that such a table can be generated with interpolation. On the page linked below, there's a heading "Charge Termination Condition" under which an explanation and a table are given: https://nordkyndesign.com/charging-marine-lithium-battery-banks/
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    Is my LiFePO4 battery capacity diminished or am I just on the flat part of the charging curve?

    Hi @Smokin ... That's an interesting theory as to why the battery seemed stuck at 13.6. I may try to measure this. How does the following plan sound? 1. Disconnect the charge controller wires from the battery 2. With the charge controller on, measure the voltage across them where they would...
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    Is my LiFePO4 battery capacity diminished or am I just on the flat part of the charging curve?

    Thanks @mikefitz ... The article by Eric Bretscher was largely over my head, but I learned some things from it anyhow. I actually have no idea how my charge controller decides when to stop charging. At this point, I'm trying to figure that out through observation. I believe this. I'm now...
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    Is my LiFePO4 battery capacity diminished or am I just on the flat part of the charging curve?

    Hi @mikefitz - Thanks for sharing this. Is there a formula for calculating the current that indicates full charge for a given voltage limit?
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    Is my LiFePO4 battery capacity diminished or am I just on the flat part of the charging curve?

    I have two 200W panels for a total of 400W. I'll edit the original post for clarity. OK! This is interesting. I'll have to watch out for this falling current. It seems that if I see the current fall as the battery voltage approaches the limit I have set in the charge controller, it means the...
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    Is my LiFePO4 battery capacity diminished or am I just on the flat part of the charging curve?

    It's probably doing 20 - 25 amps for at least 3 hrs a day I would imagine. I've only been there to see it stay at 13.6V for 10 min or so. When I saw the voltage seemingly stay constant, I got concerned and shut off the panels. I think the battery monitor is reading correctly so I believe you've...
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    Is my LiFePO4 battery capacity diminished or am I just on the flat part of the charging curve?

    Hi All I'm a newbie and hoping to better understand my LifePO4 battery and charge controller. System Basics: 400W PV Array (Two 200W 12V panels wired in series) 60A MakeSkyBlue MPPT charger 200AH 12V LiFePO4 Battery Inverter + Trailer Loads System Details...
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    Setting Up a Dual Pole Circuit Breaker

    Yes. I believe gnubie linked to a thread with that video 5 posts up.
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    Setting Up a Dual Pole Circuit Breaker

    Your thoughts on standards and brands are appreciated. However I am more interested in the concept of non-polarized breakers in general. Can using non-polarized breakers eliminate the dangers and complexities of polarized breakers (such as those considered by @Hedges above)? I didn't read the...
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    Setting Up a Dual Pole Circuit Breaker

    What about using non-polarized circuit breakers like this one? Is it non polarized because it doesn't have an arc chute (a.k.a. arc extinguisher, snuffer comb, etc.)? Is it important to have an arc chute? I read somewhere that the arc chute is designed to minimize damage to contacts, but that...
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    How can I safely make sure charge controller won't over-charge battery?

    Hmm... The Amazon page for my battery indicates it has 8 cells, not 4... Does that change any of your recommendations, @Hedges?
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    How can I safely make sure charge controller won't over-charge battery?

    Nice! I'm thinking I could keep the amps in that range by using 1 panel. Seems possible. I'll do some research into the battery... Battery manual has its own chart. Interesting... Might need to think about getting a different charge controller. But first, I'll try lowering the "highest...
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    How can I safely make sure charge controller won't over-charge battery?

    A big Thank You, @Hedges, for digging deep to help me It looks like I can set the "highest charging voltage" (D02). Right now it's at 14.5. Charge controller manual says Overcharge Protection Voltage - 12V Bat: 15V Battery manual recommended charge controller settings says Over Voltage...
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    How can I safely make sure charge controller won't over-charge battery?

    Hi Folks I'm a solar newbie and recently setup my 1st system. I have been monitoring my battery's state of charge (using resting voltage at first, and later, a battery monitor). I manually shut off the solar panels when my battery gets close to full because I am not confident that the charge...
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    Newbie seeks feedback on off-grid system plan

    Interesting idea. Thanks for sharing that. Gotcha. Thanks. I'm afraid the hot negative scenario you described is a bit beyond me as I believe I am lacking in some basic electrical understanding. But disconnecting 2 wires instead of 1 for safety makes sense intuitively. Anyhow, I appreciate...
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    Newbie seeks feedback on off-grid system plan

    @MisterSandals This is the idea I am promoting.
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    Newbie seeks feedback on off-grid system plan

    @Hedges Thanks for your input. Some questions... Why do you suppose the NEC requires it? Why do you like to do it? I'm guessing the answer is "redundancy". What does "two poles in series" mean? The breaker I have is like this: DC Circuit Breaker Short wire conducting heat out of the ends...
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    Newbie seeks feedback on off-grid system plan

    I was referring to a different calculator that goes down to 18awg. I can make my point using the one at calculator.net though. Here's the same set of values you used, but with 0.02 feet instead of 1.5 feet: I understand this is may not be a very common example. But there are realistic...
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    AiLi shunt question

    For convenience, here's the part of the manual that I think is being discussed:
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    Newbie seeks feedback on off-grid system plan

    @MisterSandals I think the answer to this is "not necessarily" Decreasing wire length decreases voltage drop. But I don't think wire length affects wire temperature while carrying current. If we had an 18 awg wire carrying 200A, we could get the approval of a voltage drop calculator by putting...
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    AiLi shunt question

    I might actually set mine up today. May have more to offer later...
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    AiLi shunt question

    Is the monitor prompting you to specify the battery voltage? Theoretically... the monitor could detect the battery voltage by itself... Not sure if it does.. The manual says there's a step where you can tell it at what voltage the battery is considered to be at 0% charge. Are you seeing that...
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    2-pole circuit breakers

    @JoeHam Thank you. I am compelled to offer the standard disclaimer: "I searched the forum but didn't find it." You did though! Thanks for providing the link to that discussion. I will dig into that later. ^ Sounds like wisdom. @rmaddy Thank you. Sounds like good advice. I have some 250V DC...
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    Understanding Breakers Between Panels and Charge Controller

    I kid you not, I just stumbled across this guy talking about the PV breaker issue. He's saying exactly what I was thinking... Here's the video, queued up to where he starts talking about PV breaker amperage:
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    Understanding Breakers Between Panels and Charge Controller

    @Supervstech Thanks for your reply! For the panels I'm working with, the current at pmax (Imp) is 11.76A. The short-circuit current (Isc) is 12.45A. The panels will be wired in series. It seems that the difference between the current that we want/expect from the panels (Imp) and the maximum...
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    Understanding Breakers Between Panels and Charge Controller

    I see people recommending using a circuit breaker between the solar array and the charge controller and I'm not sure why. Is it true that solar panels can be shorted without damaging them? If a breaker were sized above the short circuit current of the array (Isc) what scenario(s) could cause it...
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    2-pole circuit breakers

    Hi Folks I have MakeSkyBlue 60A MPPT charge controller. The manual calls for two 2-pole circuit breakers to be installed like this: For the breaker between the battery and the controller, for example, I assume it would work to have a single-pole breaker on the positive wire only... Is there...
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    Newbie seeks feedback on off-grid system plan

    @MisterSandals Interesting! Thank you...
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    AiLi shunt question

    Hi - I'm going to be setting up an AiLi monitor with a 350A shunt soon. So I can't answer from experience, yet. In the mean time, here's the manual and a YouTube video: Manual YouTube Video
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    Newbie seeks feedback on off-grid system plan

    @MisterSandals OK - Thanks for checking that and providing the link to the tool. So are voltage drop and wire heating two sides of the same coin? In other words, if voltage drop is under 3%, will wire heating be at a safe level? On that calculator, do you know what Power Factor is?
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    Newbie seeks feedback on off-grid system plan

    Thank you! I forgot about this. This got me thinking more about the breakers... The charge controller instructions specify that the input and output breakers should be 2-pole and should have positive and negative wires connected to them. In my drawing, I have breakers only on the positive...
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    Newbie on the Central Coast of California seeks advice

    Hi MisterSandals! Thank you. My friend bought all the major components without much planning. Fortunately, everything but the battery is returnable. We haven't done a proper energy audit, but the system is roughly based on a neighbor's system. I hope you'll check out my post in the DIY Solar...
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    Newbie seeks feedback on off-grid system plan

    Hi Folks I'm new to electrical / solar stuff, but I've been reading up online. A friend of mine is moving to an off-grid 5th wheel and I'm trying to help her get a system set up. I'm hoping to get some feedback on my plan. Here's a sketch of it: Here are some specs on purchased components...
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    Newbie on the Central Coast of California seeks advice

    Hello forum folks. Putting my first post here to introduce myself. I'm Eric. In live on the Central Coast of California. I do quality assurance work for a mobile game. I'm trying to help a friend set up an off grid solar system for her 5th wheel. When I started, I had very little electrical /...
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