I built a 12V, 270-280Ah battery for about $650 once all the parts were accounted for. If I'd tried to build ~200Ah it probably would've been $550, give or take. So about half the cost of the SOK (though IIRC the BattleBorn batteries I was originally comparing pricing to were around $900 for 100Ah).So, I’m seriously considering building a DIY battery. Watched Will build a few on YouTube and it looks like fun, and a good learning experience. A while back Will built a 12 volt, 200 amp hour battery with Fortune cells and a Overkill BMS. The 8 cells cost about $960 ($120 each), and the BMS another $142, which totals $1102. The Overkill BMS also has Bluetooth and a great app. Then I saw him review an SOK 12 volt, 206 amp hour battery - which he highly recommended - at a cost of $1029. In that review video he states “you can make your own battery for much cheaper”. I’ve also seen many other YouTube videos where this is stated as well. So, I’m a little confused, and am probably missing something very obvious. Am I comparing apples to apples? Can someone please shed some light on this subject. Thanks!!
The larger the battery you build though, the more savings you'll get per Ah. Basically the BMS, wiring, terminals, fuse, compression method (rods/nuts, foam mat, or tape), battery case, etc are all a fixed cost... about $200. The cells are the only thing that really varies. So there's less savings (per Ah) if you build a 100Ah battery than if you build a 300Ah one, since you spread the fixed costs across the larger battery. You can see my parts list here:
In my earlier post, I talked about what LiFePO4 batteries were and why I went with them. In this article I’ll cover how I built mine, which should allow most savvy DIYers to more or less repe…
DIY will probably be cheaper. If you have to buy all the tools needed it won't be as great a bargain. The $650 above doesn't account for the bench charger I bought, for instance, but I will use that for other projects so I'm ignoring the tool costs.