High Power 10s Lipo Battery Pack with BMS

Beautiful and well thought out! It’s like the matrix, I’m starting to see the code! Thank you bro!

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Open the motor and count the magnets in the shell. This motor has 14 magnets (poles) or 7 pole pairs multiply voltage x KV rating to get RPM multiply pole pairs x RPM to get ERPM

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Good info, thank you sir. I am slowy getting my head around all of this :slight_smile:.

Your very welcome, About the TB 260kv motors, I used to run those. They are good motors with a good torque and speed. Their shafts are long enough to accommodate the wider pulleys and belts. They also are well made and come with quality NSK bearings. I ran them at 12s with Hobby ESC’s on 90mm wheels and got 28mph going uphill.(just a slight grade) When I upgraded to Vesc’s I switched to 190kv motors and 10s because I was afraid of causing DRV fault in the Vesc. But, I think that you could possibly run them at 10s with the Vesc if you turn the max erpm limit down from 100k to 60k in the bldc tool. This is only speculation by me for I have not tried it and I am by no means an expert concerning the Vesc.

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Mine is allready at 60k MAX ERPM, I thought that was the most it should be because of DRV issue?

I am running a 6355 190kv right now until my replacement gets here, if I raise it to100k will I get better performance? It’s slllloooooowwwwwww right now :slight_smile:.

Ideally, I would like to run dual 6355’s, but I am still waiting on my 10s pack and DIY is out of stock on VESC’s for a couple of weeks and I need to get another motor, so Ill probably go with 190kv at that point.

I don’t think upping the erpm limit will help performance. However, your other settings will. Post screen shots of your other settings in bldc tool and lets have a look. Also are you running 10s voltage?

I am currently running 6s (x2 zippy 8000mah 30c Lipo packs), but I am going to 10s when my new pack gets here.

I am really confused by the math regarding the VESC and Motor KV values, mostly because I’m missing so much of the math for a full understanding. So if I have this right…

8600 / MAX Voltage = MAX KV then 8600 / 42.0v (10s) = 204kv so 204kv would be a theoretical maximum that can be used on the VESC. But that is dependent on the MAX ERPM limit being at 100k?

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motor kv means rpm per volt. So, 200kv means 200 rpm per volt. So, 200kv x 42v = 8400 rpm or, 190kv x 42v = 7980 rpm The max safe erpm for the vesc is 60k 8400 rpm x 7 pole pairs = 58800 erpm You could safely run 200kv motor at 10s without having to worry about erpm limit.

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6s voltage is minimum for e-skate and is probably the reason for the lack luster performance. especially acceleration. Upping the voltage to 10s will make a big difference. Your motor max (60a) and batt max (60) are plenty high enough. The only thing, you might try switching from watt control to current control in the PPM settings. I don’t know if you’ve tried that but it may make a difference. I run in current mode myself.

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More on voltage, I have run 6s, 10s and 12s. Even the difference between 10s and 12s is very noticeable concerning acceleration. 10s is smooth and manageable. 12s is very snappy and requires much more caution when squeezing the trigger. 6s is the most controllable and is good for crowded sidewalks like the boardwalk at the beach where speed and acceleration is not needed.

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What setting would I change and how to define the value for that setting if I wanted to run 260kv motor or motors at 10s? Or is that even possible? Is there a method of including the ERPM limit into the formula KV * MAX Voltage * 7 = ERPM?

I have always run 6s up to this point but my range is not great, that’s why I wanted to go to 10s on my everyday board. Eventually I want to run dual motors, but I have some product to buy first.

Thats the formula. KV x V x 7=ERPM Provided the motor has 14 poles. There are some hub motors that have more.

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have you ever tried running in current control mode?

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I think it is possible but I am not sure. the setting is on the first page and you already have it set at 60k. Chaka is an expert on the vesc and could probably give a better answer.

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When I asked about including the ERPM limi, what I meant was how do what is the math to define the ERPM limit for a motor with a higher KV than is supported. I don’t even know if its possible, I’m just trying to figure out if it is.

@chaka, do you have any info that could shed some light on the problem of how to define the ERPM limit for a motor with a higher KV than is supported?

I originally ran Current Control Mode until @Ackmaniac released hiw Watt Control Mode. I found I got better performance with WCM on 6s.

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the motor doesn’t have an erpm limit. only the vesc has the erpm limit. the max erpm that a motor will produce is determined by KV x V x pole pairs

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I get that. I was referring to when you said…

When we were talking about 260kv on 10s.

I am trying to figure out if its possible to run the 260kv motors on 10s by adjusting the ERPM limit. IF so, whats the math to define what the ERPM limit should be? If that is possible.

Sorry if Im not being clear, it may not be the ERPM limit that is critical but that’s the limit that I am trying to avoid passing so as to not burn up the DRV on the VESC.

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the erpm limit should be 60k because thats what the vesc can handle. theres no way to adjust the erpm of the motor except by lowering or raising the voltage supply. the KV of the motor is set and can’t be changed unless you re-wind the motor. What I was suggesting is that setting the erpm limit in the vesc via the bldc tool to 60k which you have already done might be enough to keep the 260kv motor with 10s voltage from overloading the DRV chip. But I am not sure about this. I haven’t tried it so it’s only speculation on my part. I would ask someone like Chaka about this before trying it.

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Cool thanks for letting me bug the crap out of you :grinning:

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no problem, I enjoy taking about this stuff

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