Remembering that we are addressing the question: "
How well do you think 4 of these cells would work in a van?" and with the understanding that I am only comparing
between different LFP cells, here are my thoughts, understandings, and clarifications on the above:
1. Robust physical construction
The point (in context of the question: "how well do you think 4 of these cells would work in a van") is there are other cells (Frey/Fortune, CALB, WInston, Sinopoly), that are substantially more physically robust and better suited for harsher use (both in terms of casing and terminal strength and construction).
I am not weighing in on whether these (280 EVE) cells are or are not usable in that context, just that on a spectrum of strongest to least strong physically, I would not put them near the top, for many people this won't be a concern, for some it will, depends on use-case.
2. Small Cell Size
I think you have misinterpreted the point on this one (my fault for not being more clear). Point two relates to
cell size, not pack size, and it is about strength not space efficiency (point 3 is about space efficiency, and these cells score well in that respect).
This has to do with the internal cell integrity in high shock/vibration environments. As a single cell gets larger it gets weaker. Best practice in the marine world--at least for small-medium crafts is <200Ah cells, ideally 100Ah or less (and these capacities refer to the already more robust nylon cells). If interested you can read more in the Nordkyn Design series.
How important this is for you will probably depend on your usage (and to an extent how you construct the pack and the lengths you go to protect the cells). If the places you go are pretty tame, probably not worth losing any sleep over, if you push your vehicle and are frequently offroad, on washboard, etc, I think it becomes more important to consider the marine best practices.
I think this is one area where compression vs non-compression could make a substantial difference.
4. Well matched (in capacity and internal resistance)
I think this is a misunderstanding of what
well matched implies,
@Steve_S has covered this in detail pretty well here and elsewhere as have others. The basic matching the grey market resellers do (unless you have learned something new from one of the suppliers) is rough at best. My understanding is: A static IR check with a $40 test meter, A mid-SOC resting voltage check with a multimeter, and possibly a capacity test but no clear matching or sorting.
I don't want to dwell on this point too much as its not specifically relevant to van/vehicle based systems and has been discussed before, and alternatives at a similar price point are not guaranteed to be better matched (though from what I've seen CALB and Frey cells often seem to be--but are more expensive).
The main point I want to make is these cells are loosely matched, not well matched, and at this price point and for this application, that is probably just fine. But if you look beyond us cheapskates on this forum
, you will come across a lot of knowledgeable folks and businesses who would not even consider the cells we are buying, some have applications that necessitate better quality others just have somewhat higher standards.
I suspect this may come across as overly negative (I hope not). Its not meant to, the above is only considering the technical merits of the cell in relation to a van build. When you factor price in (which lets be honest, this is
the reason virtually everyone buys them), there is a compelling case for buying these (or similar price/quality grey market cells). These cells are not #1 in any technical category best I can tell, but they are #1 (or were) in Watt-hours / dollar, and for most people that is very very high up their priority list and quite a large selling point. If a cell can be acceptable quality at a great price, that is a good val
