hexfly 5800 life expectancy
 

TR-MT8E, It has two hexfly 5800 lipos in parallel. I use the car 3-5 times a week and balance charge them every time. When discharged they show about 3.75 volts per cell.
My questions are: What will the batteries act like when they are reaching the end-of-life phase? If one battery is acting OK and the other is going away, should I replace both?

thanx

Treat your batteries well and they'll treat you well...most of the time.

I've had to put two 3S packs down this month because of one cell in each pack acting up. For me, it was watching the voltage ramp up to 4.2v very quickly on one cell when all three cells were at 3.8v at the beginning of balance charge. After waiting for the 3S packs to finish balancing....two + hours....at 1C charge rate, it never happened. That one cell had outrageously high internal resistance compared to the other two cells. Also, that one cell with high IR, was always the lowest voltage cell after my ESC's LVC kicks in.

I do believe there are differences in quality of LiPo batteries. The two 3S packs that I just got rid of were my newest batteries, and were only two years old. My first four 2S LiPo batteries from 2010 are still going strong, and with relatively low IR numbers.