so this has been driving me insane for like two weeks now. built a 5inch freestyle quad, running a 45x45 stack, speedybee f405 with their 50a 4in1 esc. motors are t-motor f60 pros, 2306 1750kv. on 4s lipos, 1500mah. flies totally fine cruising around, smooth as butter doing flows and stuff but the second i do a hard snap punch or a really aggressive throttle up from a dive it just cuts out for half a second and comes back. not a full crash, just like... hesitation.

ive checked the betaflight logs and it looks like voltage is dipping hard, like 3.1 or lower per cell for a split second. i honestly cant tell if its the battery, the ESC, or if i have some kind of capacitor issue. i did solder a cap on the battery lead but its a pretty small one i had lying around, maybe 1000uf 35v. i dont think i even know the rating of the lipo anymore, its a geprc brand one that came with a kit deal.

anyone dealt with this before? wondering if i should just throw better batteries at it or if theres something else going on

yeah almost certainly the battery tbh. kit lipos are usually garbage, geprc includes them as like a freebie bonus thing and the C rating is basically fiction. a 1500mah 4s doing hard freestyle on f60 pros is already kinda asking a lot and if the internal resistance is shot youre gonna see exactly what youre describing. grab an isdt q6 plus or similar and do an internal resistance check on each cell, if any of them are above like 5-6moh each youve basically got your answer.

the cap thing is a bandaid anyway, not gonna fix a weak battery, it just helps with shorter voltage spikes from the ESC switching. if you want to actually fix it properly get a tattu r-line or an xt60 gnb and see if the problem goes away. bet you anything it does.

had almost the exact same issue on my build last year and it was the cap for me. i was running way too small a cap and it wasnt doing anything. went up to 2200uf low ESR and it helped a lot. still think the battery thing the other guy mentioned is probably the main culprit though, both things at once is pretty common