So it doesn't happen if you hold the throttle down continuously and take it up to it's highest speed? Are you sure that it's not cutting out on the way up to top speed? Cuz that's what mine did when it would trip the BMS. We need to know whether the LI-ION is really LI-ION or if it's LIFEPO4 and also does the battery have a BMS? Also, does the Infineon controller have a voltage cutoff limit? If it really is LI-ION or Lithium polymer then it's not a BMS problem because those batteries can handle really high amps. If it's LIFEPO4 then it's probably the battery tripping the BMS. Did you buy it off e-bay? A lot of those e-bay batteries are weak. You might just need a better battery. In that case, do your research. Don't buy off e-bay. Make sure you look at the maximum discharge current. It will say "maximum discharge current: 20 amps" or something like that. You're going to need a battery that allows about a 40 amp maximum discharge current and most of those batteries are LIPO (lithium polymer). LIPO and LIFEPO4 are different kinds of batteries so be careful and know what you are getting.
I'll just say that at first when the battery would trip the BMS, I originally thought it was a throttle problem but I soon understand that it was the battery tripping the BMS. And it feels like you are actually cutting the throttle off on your own but it's really the BMS cutting the throttle.