Supertux1
100 W
I've been very happy with my em3ev cell_man triangle battery a 14s9p of ICR18650-22P @ 18.5Ah running a geared hub motor MAC-10T.
However, after three years of almost constant cruising at 20-30A draws, the capacity is now less than half of what it was new, the voltage drop is very steep, and I'm getting close to LVC on my commute now. I've logged almost 8000 miles on the bikes in my signature (still working!) and I'm not disappointed, this is more than I expected! It's paid for itself a few times over saving wear and tear and gas on my car. So, 3 years later, there are so many new 18650 cells to choose from for its replacement!
Basically, I am wondering if I should choose the high capacity (29E, 32E) or one of the high energy (25R, 30Q) cells.
I will never pull more than 40A peak continuous out of the 9p pack which equates to about 4.5A per cell max. (Controller cut off, motor thermal limiting etc...) Most average cruising rates are 20A to 30A (2.2C - 3.3C) for about 35 minutes, 10 miles or so. Occasional crosstown commutes, double that range and time.
So, I know there is a relationship between lifecycle, capacity and C rates but I'm not sure exactly what from these new cells. I'd like the new battery to last just as long. I don't want to get a high power battery, not be able to use its full draw capacity and also be stuck with a lower lifecycle with no tradeoff. So, will I gain an advantage in lifecycle by choosing one of the high energy cells and only using a fraction of its capabilities, or is it more economical to purchase the high capacity cells and run it close to it's C rating?
If it doesn't really matter either way, I'd opt for the 32E for the increase in range.
Thanks for your help!
However, after three years of almost constant cruising at 20-30A draws, the capacity is now less than half of what it was new, the voltage drop is very steep, and I'm getting close to LVC on my commute now. I've logged almost 8000 miles on the bikes in my signature (still working!) and I'm not disappointed, this is more than I expected! It's paid for itself a few times over saving wear and tear and gas on my car. So, 3 years later, there are so many new 18650 cells to choose from for its replacement!
Basically, I am wondering if I should choose the high capacity (29E, 32E) or one of the high energy (25R, 30Q) cells.
I will never pull more than 40A peak continuous out of the 9p pack which equates to about 4.5A per cell max. (Controller cut off, motor thermal limiting etc...) Most average cruising rates are 20A to 30A (2.2C - 3.3C) for about 35 minutes, 10 miles or so. Occasional crosstown commutes, double that range and time.
So, I know there is a relationship between lifecycle, capacity and C rates but I'm not sure exactly what from these new cells. I'd like the new battery to last just as long. I don't want to get a high power battery, not be able to use its full draw capacity and also be stuck with a lower lifecycle with no tradeoff. So, will I gain an advantage in lifecycle by choosing one of the high energy cells and only using a fraction of its capabilities, or is it more economical to purchase the high capacity cells and run it close to it's C rating?
If it doesn't really matter either way, I'd opt for the 32E for the increase in range.
Thanks for your help!
