First I shall tackle the A123 and Samsung 25R cells
Here are some basic specs for the cells, you will notice that my continuous current values are higher than the datasheet values. This is tested maximum current for at least 5 minutes and not their entire charge. Also the volume has been calculated as if they were squares and not cylinders.
Energy Analysis
The most energy dense are of course the Sanyo GA cells with a whooping 578 Wh/L and 268Wh/kg. Not too far behind are the 30Q and Sony VTC6 cells. 25Rs have 71% energy density and 76% specific energy which is not great but also isn’t terrible. The one cell which is absolutely horrible in my opinion is the Lifepo4 cell with only 32% energy density and 40% specific energy of the Sanyo GA cell.
Power Analysis
Here is where the A123 shine. They can produce lots of power. Up to 200W per cell! The issue is they also produce a lot of heat at this high power output. If you limit them to 30A per cell they only produce 13% heat which is better than both 30Q and VTC6 and on par with the GA cell at twice the power output which is pretty incredible. The issue with doing this would be reducing the specific power and power density to the same levels as the GA cells.
Another good thing to point out is how mediocre the 25Rs are. They produce a lot of heat, 21% of the max power generated is heat. They packs good punch for their weight but get left behind by the VTC6 and 30Q cells when it comes to power density.
The GA cells only produce 13% heat but they also only output 50% the power of the 30Q and VTC6 cells both of these cells are more efficient at 15A producing only 8.1% heat. The 25Rs produce 14.8% heat at 15A in comparison.
The cells that shine the most here are 30Q and VTC6 in my opinion by producing almost 95W per cell and keeping the heat produced relatively low. They pack the most power for their weight and size when you take into account that the A123 need a heatsink in order to take full advantage of their 70A rating. Plus both of these cells can do higher bursts of power as long as the temperature stays below 80C.
Cost Analysis
This is where the A123 fall apart and the 25Rs start looking like not such a terrible cell.
The A123 only bring 0.89Wh/$ to the table while the top three are well above 3Wh/$.
They also dont bring the best to power per dollar to the table, in fact they come in third just barely edging out VTC6s 20.78W/$ to 20.40W/$. The top two produce above 30W/$.
The 25R cell is the most economical one with 3.59Wh/$ and 34.1W/$. The downside being that you’ll have to have a larger and more inefficient pack whether you want power or endurance.
In my opinion, the 30Q is the best cell overall when taking into account cost. They are slightly inferior in every way to VTC6 but they also only cost 66% which is not worth it to me. The GA cells are the best for endurance packs but the 30Q cells cost 78% of them.
@SirDiff
@Okami
Once I add Lipos to the top end, you will see how these are wedged out of the race, since Lipos cost even less than Li-ions and have a higher power density than lifepo4s