LifePo4 Lithium Iron Phosphate Battery

OK, good question.  All that good work knowing the electronics and its the case that holds you up!  Have a look at these...

https://www.amazon.com/MTM-Divided-Ammo-Crate-Utility/dp/B0DTQBXR51/ref=ast_sto_dp_puis?th=1
https://www.amazon.com/MTM-MGC-Mobile-Water-Resistant-Stackable/dp/B0C1DHC3PN/ref=ast_sto_dp_puis
https://www.amazon.com/MTM-TRC39-Tactical-Water-Resistant-Ring/dp/B0C1DF8GFJ/ref=ast_sto_dp_puis
https://www.amazon.com/MTM-ACDC50-Resistant-Lockable-Stackable/dp/B0DTQBXR51/ref=ast_sto_dp_puis?th=1

Or this:
https://www.amazon.com/dp/B0C1DHC3PN?ref=ive_vftp_hero_cx_pfo_vse-cards-ingress0

And this:
https://www.amazon.com/MTM-MGC-Mobile-Water-Resistant-Stackable/dp/B0C1DHC3PN/ref=pd_sim_hxwPM1_sspa_dk_detail_d_sccl_3_2/137-5852126-9970633?pd_rd_w=6aj9X&content-id=amzn1.sym.3a852a98-d65f-4301-9bd0-9b589b14d1ef&pf_rd_p=3a852a98-d65f-4301-9bd0-9b589b14d1ef&pf_rd_r=6W0EQ6A2V92EHKCW7V06&pd_rd_wg=QT2Ts&pd_rd_r=8f491406-085b-4b19-8e9a-17b52cadef29&pd_rd_i=B0C1DHC3PN&psc=1&sp_csd=d2lkZ2V0TmFtZT1zcF9kZXRhaWxfdGhlbWF0aWM=

I don't know if anything is going to fit perfectly, but the last two might be good to both hold the cells and leave room for some of the hardware that you will need.


I would LOVE to know how your 48 volt system will work!  At the moment I am thinking about bumping my next build to a 24v system.  I thought I was special until you came along with the 48v system!  Now I have battery envy!


Eric

John,

There are some good cases in the links that I gave you.  But if these are not going to fit, then I would go and make my own case.  This is not as hard as it sounds.  I might be tempted to go with a good hardwood for its durability (I would buy the pieces of hardwood from a store that sells them in sheets) or maybe just go with some pine or poplar due to the ease of drilling and screwing various sockets into place.

Whatever choice I go with, I would thoroughly stain and then varnish the wood.  I would think carefully about what I wanted for the final finish--it would be waterproof and fairly hard so as to resist dings and scratches.

The beauty of this system is that you could make the case to the exact standards that YOU want.



ALSO......

Maybe consider including some way to make the battery portable.  I am sure at some point you will want to move the battery inside for maintenance or to replace a component or you will find a way to make it better.  Whatever the case, I am sure that it will be better to have the case mobile so that it can go to your shop as opposed to having to work on it outside.  Perhaps you include a way to attach wheels to it but only have them when you are moving?  Maybe you can think of something else.



Whatever the case may be, I am getting more and more eager to see what you construct!


Eric

Eric,   Thank you for your references.  As I was poking through them this weekend, I went down additional rabbit holes trying first to see if there is anything in the DIY battery world that would even come close as well as investigating durable polymer cases that would fit the plans.  Just to recap, for the golf cart....short of selling my current one and buying another used one with greater battery compartment size flexibility.....I'm pretty limited to something 7" wide.  This is standard GC2 lead acid battery width and indeed some LiFePO4 manufacturers sell dedicated 36V or 48V single batteries to fit these compartments (single batteries still needing to be connected in parallel to 1, 2, or 3 additional identical batteries for any useful performance).  Although I will have to re-measure to be sure, I suspect one long ~30 inch container box that is 7" wide, if durable enough to withstand the weight,  could accomodate the requisite 16 prismatic cells in linear array and potentially still have room for the BMS.  If need be as well I could exercise the option that you mentioned....building them from scratch out of wood and applying the desired flame retardants for fire protection.  

Another option that I may resign myself to is to stay at 36V with the golf cart and build a separate set of boxes at 48V for our basement where the racked array would be poweirng, through a charger-inverter, a 220V deep well water pump, the propane furnace fan and associated electronics, and potentially some sump pumps....all for emergency back-up use only.  Yet even here it *may* be possible to build the long, linear array of cells for 48v, ..... just not as necessary since the space requirements are not so crucial.  Cells for the 36V build for the golf cart would fit in a shorter box as excpected.  I'm pasting below some containers I located online, although some like the TEMU vendor I've not dealth with and am wary of quality from here even if not based on experience.  Modifications would need to be made to the case(s) for preference and safey, but durability might be okay.  Cells (100 Ah) from either EVE or BYD would fit these with some room to spare.  I could even buy a bit on the long side for the case and cut it down to fit with a reconstruction of the cut end.  Along the way here I'm trying to gain knowledge about what makes one battery/cell type better for the amperage bursts of electric vehicles vs batteries considered adequate for home power systems...any insight here would be most welome.  By doing a DIY of the battery build and assuming good components and 'operator competency' ( here's hoping!), the savings seem pretty substantial and the knowledge gained quite gratifying.  Will try to continue with updates here as progress is made.  Thanks again for the comments and links, Eric!...

John,

Yeah, I was thinking about those limitations when I was looking at containers.  It seemed like nothing wanted fit the batteries without getting preposterously huge.

The only other option I had was maybe you could fabricate a custom metal enclosure.



Eric

Since my post got wrecked by my phone, the short version is SendCutSend, PCBWay and other places online (no first hand experience) cut and in some cases fabricate boxes and other things from the various materials they offer.

It's probably a good idea to use bulkhead fittings to pass the wires through and mount the BMS on the outside vs try to cram things in with the cells and risk an accidental short. You want the cells to stay together and not flop back and forth while driving, so keeping it somewhat tight and padding the remaining free space will stop that from happening.