Hey guys, I was just on here looking for some battery build tips, and I’d like to point out that this comment from treenutter :“Not quite; it means you have 10 sets of 4 cells wired in paralell. Then you connect those 10 sets (with 4 each) in a series to increase voltage”… is wrong according to Jason Potter’s (onloop) site.

Regarding the Spacecell 10s4p he states:
The battery is 10S4P meaning it has a total of 40 Cells, 4 Parallel groups of 10 cells in series. Samsung 25R Cells.

So now as Ali G says “I’s well confused!”

10 Cells of Samsung 25r’s in series (nominal voltage of 3.6 per cell at 2500 mAh) would produce a single pack of 36volts and 2500 mAh (or 2.5wh) correct?

Wiring 4 of those 10 series packs in parallel gets me 36volts and 10,000 mAh (10wh) of power, correct?

Conversely, 4 of the same cells wired in Parallel gets me a 3.6volt pack with 10,000 mAh of power. 10 in series gets me to 36volts at 10,000 mAh of power.

So my question is, is the advantage to have more packs for a BMS to manage? The more micro-managing that can be done the longer the pack lasts?

Or am I missing an advantage in Discharge Rate? From what I’ve read, Samsung 25r cells have a 5c discharge rate. Thats 5 times the capacity of 2500, or 12.5 Amps. Multiply that times the number of parallel groups correct? This would be a max “c” discharge rating of 50Amps for the battery built with 4 parallel groups of 10 in series, and the same for the pack made with 10 4 cell parallel packs in series? Just remembering that cells in series increase voltage and cells in parallel increase capacity.

It seems to me there is no advantage either way? Am I missing something? I’d like to get started on a build but the conflicting information out there has me confused a bit…