How many charge cycles before I should expect to see a SMC 5200 24C lipo start to fade?

SHOULD get close to 500 cycles, but SMC has gone downhill. Many guys are having trouble with fewer than 50 cycles.

Hmmm...I have between 50-100 and have a noticeable performance drop off after about 5 minutes of running in my 17.5 SC10.

Well there is other possibilities, maybe your slipper is overheating? Is the 17.5 new or has it ever been run hot? I would guess the battery first, and try to find a known good one to test with.

I would assume you balance them fairly regularly, but in case you don't...

I ran a battery for about 10 charges w/out balancing and it seemed to suffer performance wise. After balancing it and charging again, I realized that it was probably out of balance and would not charge fully. It went from 800-1200 mah charge from before to 2600mah charge after balancing. It seemed to run short, but after balancing, it was strong again.

Depends a lot on far you run it down. If you only use 80% of the capacity a lipo will last a lot longer according to everything I’ve seen.

Also lipos don’t like being fully charged at cold temps.