Need to know RPM of Torque Boards motor

Hi, forgive me if i’m posting this querry in the wrong place. I’m trying to establish a good gear ratio for a board with a 12 inch scooter wheel mounted through a cutout in the center. I have a Torque Boards 6374 190 kv motor that I’m having trouble figuring out the maximum RPM of. I found a formula that requires the number of hertz, which i cant find an answer to either. The formula is (hz x 60 x 2) / number of poles.

My plan was to use an 80 tooth wheel cog and 16 tooth motor cog , which I bought from electricscooterparts.com. The 80 tooth is the biggest wheel cog they sell. I asked for feedback on here about my choice of gear ratio and was told that unless my main goal is top speed I should go with a higher gear ratio. I’m guessing that means there wouldnt be much get up and go with my 12s5p, 36v, 14ah, 480wh lithium battery. Can help me find the hertz and or rpms of my motor. No literature came with it.

200w

joke aside, the maximum rpm of the motor is determine by the voltage and kv values
12s (50.4v) x 190 (kv) = 9576rpm of the motor shaft

plug that into the ESN calc and u get

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Maybe he has a 12s LIFePO4 battery instead of li-ion?

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12s lifepo4 is 43.8, still way off from 36v :rofl:

Well nominally its 39.6v which is better

:man_shrugging:t2: there aren’t that many people using lifepo4, but sure 12s lifepo4 using nominal voltage calculation is “close enough” to 36

What bugs me is 480Wh / 14Ah = 34.3V which isn’t close to anything…some weird battery fuckery going on here

Oh man, i really stepped in it here. Battery fuckery, love it! So i furnished the wrong ah, it’s actually 10. I’m pretty sure it’s lithium ion. Here’s a pic.

Definitely a 10s5p li-ion, but there’s no way the capacity is right…either its 10Ah and 360Wh or 480Wh and 13.33Ah

Wow, sorry guys. I should’ve verified those numbers before i posted my querry.

No worries lol, but in regards to the earlier question you will have a maximum motor shaft RPM of 7980 and switching frequency of 1862 Hz

Thanks ZT. Do you think the mis-labelling is going to cause me challenges going forward?

Awesome. Thanks a lot!

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yes, when the bms cutout and send u flying like superman

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Uhoh. Well, thanks!!

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Do you think i could sell it on here for cheap price? With full disclosure of course.

u can try to sell it, but idk who would buy it :man_shrugging:t2:

Bummer. Was just kidding though. I guess i’ll just chalk it up to just another cost of my esk8 education :-/

Is there a way to test the capacity?

Not really, at least not easily. You’d need to drain the battery and measure how many amp hours flowed through some current shunt

Theoretically you could get one of those $20 power meters off Amazon which tracks Wh used and connect the battery to a load (maybe a 50W resistor or something with a fan) and let it run until it is 30V (that is ‘dead’ for your battery), but it’s not particularly accurate