LOL, you are correct that the marking info calls for 230mAh and even if you buy a Beta75 BNF, it will come with a 260mAh (contrary to the marking doc) as I bought one and returned it promptly since it would not do more than 2:15 of flight with a 260. I guess I got that info from a support tech and it’s the 75s doc that recommends 550s. Sorry bout that. https://betafpv.com/collections/brushed-bnf-drone/products/beta75s-bnf-micro-whoop-quadcopter
I opened a support ticket and was told that the 2XX batteries worked OK when they used the 7x20 14000KV motors but when they moved to the 17500 motors, it was inadequate. Based on the chi-english, I inferred that 2xx sized batteries were always inadequate.
The 75, 75s and 85 frames were made for 5XX sized batteries (specifically BetaFPV’s 550mAh) but they do come with an adapter for putting undersized batteries in it. But I found that 2xxmAh batteries just don’t work with a 32g (75) and 38g (75s) quad. They get way to hot after a couple of minutes of flight and are underpowered and don’t give the runtime “documented”. Once I built up another 75 and 75s from BataFPV parts from Amazon and switched to the BetaFPV 50/100C 550mAh batteries, the 75 and 75s quads were a completely different machines. They finally had the punch expected and I get 4 minutes on the 75 and almost 5 minutes on the 75s flying a smooth indoor course.
Also, I tried my 1 year old eFlight 500mAh batteries from my nano QX2 and while they were better than the 230s and 260s, they were inferior to the BetaFPV 550s in punch and flight time. However, all 5 of my eFLight batteries had a LOT of flights on them so their poor performance might have just been age.
Check out the thread I started a month ago… BetaFPV 75mm 7x20, 75mm 8x20 and 85mm 8.5x20 whoop frames
I’m still waiting on the 8.5x20 motors to build up a Beta85 and test it.