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If what you are trying to discourage is, melding solder into the end of a stripped piece of wire before crimping, then I would agree. Compared to for example marine wire, the very thin amount of "thinning" (I do not have a spec) is going to have almost zero mechanical effect on a crimped wire as...

I got a notification that the 32 cell purchase has shipped (it took about 20 days to actually ship due to a delay from EVE). Amy provided the capacity data as well as pictures that you can find in the attached spreadsheet. Here is the raw data The raw unordered 32 cells have the following...

So in the first post, it looks like OP just dumped a bunch of sand on the lower level. At this point, I don't know if he was mixing cell capacities in that level or what configuration it might have even been in. We don't even know if the pictures of the disassembled cells are even in the order...

Pictues showing the initial assembly using the thermal pads.

It is a fundamental principle of statistics that any population of random numbers will have an increased variance with the increasing additive count. In this case, by adding two capacities together, there should be no expectation that the combined capacity STD is smaller. So this first statement...

I ordered Qty 32 of the same at the end of Aug and shipped Early Sept. Took to the last day November. Lots of issues with shipping beyond sellers' control but otherwise all cells look very good and the same 2 cells per box shipping.

The typical marine-grade wire is Tinned factory wire. I don't know the process but by inspection, the "tinning" is very thin and not the result of the hand soldering iron with a roll of solder. I would much prefer marine grade wire that is tinned over the non-tinned wire for solar applications...

Lolailando: I'm not an expert on LiFePO batteries but I am an EE with 40 years of experience much of it in systems engineering for complex systems. There are many issues that come to bear in what you are describing which amounts to ultimately a business plan for selling batteries. If the only...

We can go back to Adda Lovelace and even before in the history of computing, but I was focused more on the context of what was prevalent during the time that the DOS-based personal computers (i.e. the PC) became mainstream. The reference made to hand-coding might lead some to believe that we...

So I'm not sure exactly what is meant by eddy currents, but I have seen a significant charging imbalance from charging two 4S batteries. 20 amps in with a 16 and 4 amp split because of the way the cables were run from the charger to the parallel batteries. The point is that with the flat LiFePO4...

I certainly agree and have come to some of the same conclusion, that the challenge with for example EVE cells is the packaging and fixturing for long-term safety, and is what primarily accounts for a large part of the cost differential for commercial battery offering vs bare cells...

One of the projects we (Prof Yakimemnko from NPS, myself, and another) tried to get funded through the Office of Naval Research (ONR) was a typical example of the bureaucracy. The R&D project was to develop the logical and theoretical framework (in a pilot project) which is the equivalent of IoT...

This is a classic of example of "Those that can Do (EEVblog) ; those that can't teach(Veritasium)! Based on the EEVblog's video, the answer to the question posed(by Veritasium) basically has nothing to do with the video (i.e. Poynting vectors and field theory) that describes the supposed...

It will depend of course on the type of batteries you are using. For Lead Acid the max charging voltage is about 14.4 volts and if the battery voltage gets anywhere near that it will not accept much current. So the charging current is a function of State of Charge (SOC). LiFePO will accept...

There is certainly an aggregate learning curve for the forum, and there are various sociological factors that affect the progression not related to the technical issues. While I'm not familiar with the distiller's forum, I was involved in a motorcycle forum, where (with my EE background and...

Before we get too overly technical (fat chance on that), We only have to look at different methods of actually measuring current to realize that the Poynting vector (and E&M waves) and the current in the wire are synonymous (i.e. if-and-only-if (iff) dependent in the model ). Using one method to...

Well, they are not what I consider new, you can see the top stick-on covers all lifting. They do see mt obe full capacity as I'm pulling 180 amp=-hr from about 3.45v to 11.9v. I'm pretty sure I will not be buying any more VariCore but will buying 32 280 matched EVEs from Amy

Yes, there are many things that can be done, but the problem is the return on investment. It is hard to justify the time/expense involved in this type of development for a 1 off. Although for a large house battery system the safety issues are very compelling and worth putting in the time. I have...

I think specific heat is most relevant. SH of water is 4182 J/Kg DegC for sand it is 830 J/kg degC Sand will get much hotter (5X as many delta DegC) containing the same amount of heat which means it will dissipate that heat much faster to the surrounding environment. Heat transfer (loss) is...

That would perfectly explain why they never taught the concepts this way in my EE undergraduate program. I vaguely remember the Poynting vector but it was probably in E&M II and although there was an association between Maxwell's equations and a generalization of Ohms law these concepts were...

If I was going to do any science experiments , then I would have bought the EBC-A40L . But it doesn't do much good for cell arrays especially at 48V, so I'm relying on EVE not even the vendor. If there's an issue somehow, then buying one would be the best way to deal with Alibaba if that was a...

Well he was entertaining :)

I posted this earlier in the link above https://www.academia.edu/s/8eb61f3278#comment_946018?from_navbar=true

It should be easy enough to duplicate my results. The more cells you involve in the matching, statistcially the more likely to achive overall better matches. I don't think rack-type or modular battery manufacturers guarantee any integrated bank performance (e.g. paralleled series cell...

I found several references of fault detection but this one deals with single-cell ML to detect internal shorts. The literature is rich with the methods of ISC detection in the LiBs. However, the following reasons limit the applicability of the available methods for the detection of mechanical...

This is the subject of what is called in engineering Failure Modes and Effects Analysis (FMEA). You are scratching the surface here in trying to answering the question"What happens if this part fails?". This is why I caution and criticized the ORION document because it was showing a relay...

Renogy recommends the DC-DC input side be sized for 50% excess of the output current. According to my calculation ()IIRC) a 3% voltage drop at 16 ft is about a minimum DC-DC input voltage of 12V at 14.5 alternators. I used a 40A but the voltage drop and currents will be proportionate for a 60Amp...

The difficulty I'm having with your statements is that you are treating "assumed risk" as a "roll of the dice". Once you have quantified risks and mitigated those as appropriate for the application you have a sound approach to risk management with an educated level of assumed risk. If you...

This is a very recent video discussing Compression and post stresses and the Youtuber's frustration for finding a solution. There are several prominent names from this forum and others posting in the comments. Something to follow to see what jells.

My solution to the compression problem for 2P4S cell configuration. I used 1"x2"x11 GA steel rectangular tubing to create the strong back and side structures to hide the all-thread and 3 1/2" compression springs. The 12 psi load is distributed across 8 springs that have 0.75" deflection which is...