A local racer asked for my help this week-end and we got him going. But, I wanted to confirm what we did...

He was running a Slash 4X4, Novak ESC (not sure which one) and a 7.5 motor. He kept getting Lipo cut-off within the first 3 laps of the race. Even in the pit area with a few bumps of the throttle, it would go to cut-off. We stuck in one of my batteries and it worked fine. Checked his battery on my charger and he still had 8 volts. I then noticed he was using a 3300mah/28C battery. I assumed this just wasn't enough battery for the motor he was running. Would running too small of a battery make the ESC "sense" low voltage?

Yes. More voltage drop under a high load relative to the battery capability. Possibly combined with poor condition, high internal resistance (aka IR), from age and/or storing at full charge, etc. Did the lipo get warm?

Hi Dave, thank you for the reply. No, his battery never got warm...but it never ran for more than a minute either. In the pit, it would only run maybe 15 seconds before cut-off. With a bigger battery, it did just fine. I'm pretty sure we got him covered...just wanted to make sure I was passing out the right advice

Thanks again...

You're welcome, always happy to help where I can.