3P16S has its problems also. May save on BMSs, but you lose the ability to monitor individual cells. Now you’re monitoring groups of 3. One lead to three cells in parallel only lets you monitor that one set of 3. You also lose redundancy so if one cell is bad, now the entire battery must be brought down until trouble shot and fixed. If this makes you buy busbars this gets pricey.
If monitoring individual cells is important or not, I’m not sure. I built my first Lithium and this does not allow any monitoring at all. It’s shutting off and I’m not sure why.
I thought about 2P8S for my build, but I did not want that single battery pushing the 200 amps peak or 100 amps Continuos. Part of the problem was a single BMS would handle all that power. I chose a 100 amp overkill BMS with each battery providing 50 amps continuous or 100 amps peak. Also, if I have problems with a battery, there’s some redundancy where I take one battery out and watch my power consumption, but I still have power while I troubleshoot and wait parts.
With the price of copper now, the busbars may outprice that second BMS. I was pricing 1/4” X 3/4” copper busbars for my build yesterday, and I want at least 6’, but the price I found on E-Bay was $184. If your batteries come with busbars, probably not a problem, unless when you install them 3P and they’re different than delivered.
I’m not saying 3P16S is a bad idea, just a bit more to think about in the build. For me, with all the work and time that goes into it, purchasing the second BMS was easy.