diy solar

diy solar

Recent content by nebster

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    Second opinion on Victron inverter plan

    You've gotten excellent advice so far. A few additional comments/opinions: You can parallel multiple ATs to increase capacity. Generally two Victrons is the most someone needs in USA RV land. You can also buy or commission a custom AT for your desired power. Depending on the topology you...
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    Cinergi's 28 kWh / 4 kW Solar / 10 kW inverter RV build

    Well, I certainly appreciate your rigor, in a very selfish way.
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    Cinergi's 28 kWh / 4 kW Solar / 10 kW inverter RV build

    Yeah, [happiness] = [reality] - [expectations], doesn't it? Even the high end stuff (I'm looking at you, Victron) suffers from over-zealous marketing making its way into the datasheets... it's rampant.
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    Cinergi's 28 kWh / 4 kW Solar / 10 kW inverter RV build

    Bingo. These cells are a bargain. Qualifying and then replacing a few at 96% of specification might feel good, but it is a Pyrrhic victory that places the value of our time at something like pennies per hour, for that little extra. Just assume they’re 90% of rated, or buy 10% more than you...
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    Cinergi's 28 kWh / 4 kW Solar / 10 kW inverter RV build

    You can charge, but only at half of the capacity. Some people need that other leg to contribute as well. I imagine they are pretty deterministic, yeah. I know of one rig where it was a big issue, but they had a device introducing a delay on one leg.
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    Cinergi's 28 kWh / 4 kW Solar / 10 kW inverter RV build

    Yeah, I think the main issue comes when using a 120V generator. You can't feed a single phase from one of those generators into both inverters if they are in split phase, so people in that scenario only end up able to use "half" of the generating capacity. I went up thread to look at this...
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    Check my understanding (calling on folks who understand IR)

    Yeah, definitely a small impact. But well within the realm of possibility if 3% is the difference people are observing in different places.
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    Check my understanding (calling on folks who understand IR)

    My (wild) guess is that maybe the electrolyte wicks down out of the jelly roll membrane a little bit, reducing the active surface area. I say that because new cells sometimes make a sloshing sound when you first handle them, but after a while they don't really seem to make as much noise.
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    Check my understanding (calling on folks who understand IR)

    There are definitely chemistries that require priming, or warmup cycles, before they deliver their full reversibility. There may be a small factor with LFP as well. It is the kind of detail that might not be interesting enough to make it into the public body of research knowledge. Only...
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    Check my understanding (calling on folks who understand IR)

    Well, I think there's a pretty clear indication. Look at the measured capacities at 0, 25, and 40C. Fit a curve to those values (pick your poison). You'll at least have an indication of what the temperature-related effect might be. I really think everyone is splitting hairs here (3% on a...
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    Check my understanding (calling on folks who understand IR)

    Temperature definitely affects capacity. Here's one study of small form-factor LFP:
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    Check my understanding (calling on folks who understand IR)

    Sounds good -- I'll be intrigued to see if anything changes over time.
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    Check my understanding (calling on folks who understand IR)

    How many cycles have you applied?
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    Check my understanding (calling on folks who understand IR)

    It's entirely possible that some of these large format prismatics actually undergo a capacity change during their initial few uses (and during their long passive period sitting on the pallets and boat). It stands to reason, if there are mechanical changes (electrolyte expansion, case-widening...
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    Adding second string to existing one

    Those sentences are not literally true, but they are substantially accurate. However, they don’t have much to do with the OP’s question. (Why did you write them?)
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