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It does. Thanks.

@toms, I'm about to introduce an alternator that will push rates closer to 0.5C. Would you still recommend the same settings based on the new firmware? Specifically curious about BMIN, BMAX, CHAR, and MAXC.

This depends on the firmware version (now at least). REC made some significant changes, IMO, to their charging algorithm in version 2.7 and 2.8. From the latest manual for the REC Q/Victron Compatible BMS: What can mean in practice (for me at least) is that you will get hard cutoffs...

I just fired up my Van electrical system for the first time and was very surprised by the size of the transient in spite of using the REC BMS Precharge unit set to 11 seconds. System: 24V 16 EVE 280AH cells in a 2P-8S configuration. Inverter is Multiplus 3000. The yellow trace is a probe...

Thanks so much for getting back to me! The adventure begins...

Steve, Thanks for the reply. Data from the supplier is now attached (mobile mishap). These are cells and data from Luyuan. I'm planning to assemble (electrically at least) in the 2P8S configuration shown at the bottom of page 10 of Luyuan Assembly Guide you pointed to, managed by a REC Q...

I just received my 16 EVE 280AH cells and accompanying data. I plan to bulk charge in the 2P8S arrangement and the shift to 16P for top valence. My question is on the best way to pair up the cells based on the test data I have. Should I focus on matching resistances? Resistances at low SOC...

That was concept C for me. It's not a bad idea. It's a little more difficult to find springs with the right characteristics, but they are out there.

This was the whole basis for my final design. When you account for the flex of the compression plates, which will act as two springs in series with the compression attempted by the springs, you will find that the flex of fairly thick plates (3/16 steel) is substantial. If you choose the plate...

Wondering if anyone on here has details on this subject. I just got my REC BMS powered on yesterday and started monitoring its CAN communication. I got a few surprises in what I was seeing coming across the channel. Its all documented here...

I ended up going with 3/16 steel, but not exactly for the rigidity. Based on some math, I can rely on the flex of the steel instead of using springs to provide compression in the general range we are looking for. Current design is here...

Amazing! Tell me about this mini-split!

The siglints look really good and have a good reputation. Thats what I'm saving for.

Just thinking out loud, I would have assumed that the AC content seen on the DC side would have been 2xFoutput (ie the product of AC output Voltage in phase with AC output current, which would be appear a twice output frequency cyclical power draw). That frequency shouldn't have a dramatic skin...

Skin effect is an AC effect. It results from induced an EMF that opposes primary current flow. Inducing that EMF requires a changing magnetic field, which in turn requires an AC current (the higher the frequency, the greater the effect). What ever you are seeing is likely due to something...

As I have iterated through multiple designs for compression trying to balance space constraints, it occurred to me that I wasn't fully considering the behavior of the plates. Specifically, if you put your constraints in the right location, and chose the plate thickness and material carefully...

There is industry guidance (and mil-spec guidance) for bare bus bar ampacity. Here is one source (they also have great instruction on bus bar joints): https://www.copper.org/applications/electrical/busbar/bus_table1.html

Well this is embarrassing. I do have some formal ME education. Tunnel vision is a real thing! Standby for updated calcs.

I hear you, and agree completely. Unfortunately I have some other (unrelated) structure tucked between the protrusion of the springs and all-thread such that I can't have something much thicker than 3/16 running across the face of the battery. I wish I could, this design is not an efficient...

The only thing I was planning to do about that fact was this: I'd have to think harder about accounting for it in the spring rate. I think what I lay out above is good enough, but I'd have to think about it a bit more.

Its still in the paper phase, but here is my planned design with calcs for the spring selection and compression plate thickness: github.com/natecostello/van_two_point_oh/blob/master/electrical/battery/Battery_box_design.md

Since you commented on the plate thickness, I thought you might be interested: I did the math for 1/8 Al, 3/16 Al, and 1/2 plywood. I'll definitely be going with 3/16: github.com/natecostello/van_two_point_oh/blob/master/electrical/battery/Battery_box_design.md#plate-thickness

Thanks for taking the time. I actually meant 3/16, but I'm happy to go with 1/8 if thats enough. I'm also planning to jump between those end terminals such that each cell has equal length to the other side and resistance is matched all the way along.

I'm looking to build a 2P8S 24V battery out of the EVE 280 cells. This geometry fits best in my van design. It seems like it should be fine, but I haven't seen it any any of the other designs on this forum which makes me think I'm missing something. (if you are curious, the cells will be...