Advantages of 10s?

I can hardly belive that. How fast are you going with 10s and 12s. Assuming that you go 50kmh in 10s that would translate in theoretical 60kmh with 12s. Air resistance, spin resistance and more other factors play inn and they grow almost exponentialy with speed increases. So I do suggest you try and measure the real speed differences first. And don’t go by the calculator. So here comes my 3 questions : 1)How often and for how long do you ride at 60kmh by the way. 2)most of the time people have to chose between 10s5p or 12s4p. Have you thought for the slight voltage såg that you will get with a lower available current draw? 3) Are you aware that motors also have an efficient voltage range so even if you raise the voltage could mean that the efficiency drops a bit.

So adding : Air resistance, Roll resistance, Motor efficiency Lower number of parallel cells And some other factors that I’m not remembering right know, your real speed increase is far smaller than your theoretical. Except maby downhill and in vacume.

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BTW, will running 12s but limiting erpm in VESC firmware to 10/123.7Kv be effectively as reliable as 10s? Will the VESC basically cap itself at 80 percent duty cycle and replicate 10s? That might be a reasonable way to combat voltage sag on low parallel count setups

with the new vesc versions having a higher possible amp setting (150 motor amps on the flipsky 6.6) going down in voltage need not decrease the power. maybe go 10s and higher kv motor and up the motor and battery amp settings and get even better performance than on 12s with the safety margin.

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Yeah, can’t not go to work/grocery shopping because it’s snowing/raining/whatever. But I don’t need traction control, it’s just like driving a car in snow: go really, really slow and assume you have no traction.

In those circumstances, having a robust drivetrain and knowing it won’t fail on me is part of that, and being 10S is part of that

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Just checking because I was going to run ppm cable for a nano which can’t bind to two receivers. What’s wrong with ppm? I thought if one vesc blows/loses power you will not blow your other vesc via ppm so its just as safe as having two separate receivers?

Not “just as safe” as independent, but arguably safer than CANBUS. Arguably. It depends if you want a tool or a toy…

What are the problems associated with ppm? Aside from the receiver failing and rendering both vescs unresponsive (ppm) as opposed to a reciver failing and still having another one that works ( dual receivers) is there anything else?

These types of comments make me chuckle

Bumps don’t cause this. If you are on the throttle it is the same as down hill. Except instead of going downhill with throttle engaged and never going over max speed. You are talking about wheel lift. Well the only way the wheel can spin faster is with throttle, if your on the throttle you can’t outspin erpm. And since it’s wheel lift and not downhill, if you take your finger off the throttle the wheel has no other way to increase speed.

Voltage spikes happen during braking, not acceleration. Having traction control on(which I use) also doesn’t use braking to control power to the wheels. It just cuts power to the free spinning wheel. Cutting power cannot make a BEMF higher than your pack. THE ONLY way you are getting voltage spikes is from braking. Spikes that can kill the speed controller on any Series count 13s and below is a problem outside of the system voltage.

Meaning if you get voltage spikes no matter the series count. It’s because user error. Ie you have a broken series connection so your pack spikes, or your antispark has failed, or the controller has come unplugged.

Bottom line the only way your gonna make a BEMF higher then your pack is going downhill free coasting not holding throttle and achieving a speed faster then your gearing, and then applying the brake.

So the bumps theory is out, aside from vibration damage.

Also, there’s only 3 of us on 13s that are complete, myself, pshaw, and @sk8l8r, and maybe @longhairedboy son. While I’ll support 13s all day, not a single one of you have any room to knock it. You have never experimented with it or tried it. So pretty sure my analysis of the real problems in my last post are as accurate as they can be. Failure is user error.

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@b264

VESC on 12S is fine. ITs literally all i have ever built. VESC from certain vendors who build cheap shit are not fine.

FocBox runs 12S notoriously well. It is a VESC, it was originally called the VESC-X and I still have those in my daily rider.

OllinBoardCo VESCs have ALWAYS run 12S fine… I have a pair in a bin that’s 3 years old and they still run great, i only took them out because i needed to test something else.

MayTech has multiple 100+ amp VESC 4.12 derivatives that run 12S fine and are even rated for FOC. They’re fine.

So wtf are you even talking about?

If you have room for 40 cells, go 10S. If you have room for 50, go either way, but 10S would likely be better here unless you just want 12S4P. If you have room for 60 or more cells, just go 12S.

I don’t use P groups lower than 4 cells in general, which is how i came to those numbers. There are benefits to higher count p groups. 5 in my opinion is a good balance of performance and cash.

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How has your testing been goin with the Flipsky 6.6s on 12s? I’m hopeful on those as they’re supposedly based on vesc6 and should perform just as well but since theyre still relatively new I dont see all too many about them just yet

My only issue with 13S is the odd pgroup and weird stacking required. However, if you have room for 40 cells, why not just go with 39? Bamboo sleeper anyone?

13S is fine. The FocBoxes can handle it fine. 13S will be pushing it for the Unity, but the Unity will also handle 12S perfectly well on delivery day. 13S will not run well on any MayTech 4.12 derivative to my knowledge. The VESC6 derivatives may be able to handle it. We’ll probably burn the FlipSkys up at 13S in the coming months.

I’ve also heard rumors that on the focboxes the ERPM limit is a myth. In fact, drunken discussions were had involving an experiment with focboxes and a set of NTM 270s at 12S. There may be a reality check on the soon.

My personal belief is that 12S is more efficient and runs cooler. That’s my observation, Math may say something different.

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Typical early run defects are present. We burned up a switch in one but they sent us a new one. While it was running, however, we really liked the feel of them.

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I’ve spun them upto 130k on 670kv motors. I don’t think erpm is limited within the realms of esk8 even on a 28pole hub motor.

Well, as far as I know we run most of us current control with brake no reverse. If you haven’t noticed with for e.g. 20% throttle you can reach top speed because it controls current and while current is limited motor can start spinning faster because consumption decreases and voltage increases at least that my observations when I am cruising and keeping same throttle position and board in long distance gets faster…

So if you wheel lifts up it starts to spin faster because of load disappearance?

But maybe it’s that watt mode as I am running ack firmware…

P.S. Take everything with grain of salt I am just assuming based on observations here :smiley:

I’m talking about out spinning the maximum rpm at max Duty cycle. Can’t happen if throttle is applied. Can only spin faster by external force it downhill

Also regarding current/voltage spikes, you don’t see them in your metr/other apps because of refresh rate, vesc need to implement max/min value logging because for e.g. ios app (esk8 vesv) showed max current 45A, my data logger 20times/s got 95A yesterday so its pretty interesting when you start see data you don’t normally see…

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Thank you for that confirmation. I suspected my good luck was more than just sticking with 190kv motors.

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149 kv at 10s was around 34 km/h (racing bike clocked that and was able to follow me) and 12s around 43, clocked by my wife following me by car (I wasn’t going full throttle). It’s a 50 km/h zone where most people drive a bit slower due to the many intersections.

I run high c lipo. I can run full throttle up until 3.74V before voltage sag becomes an issue and pushes the lipos below my voltage alarm settings (3.7).

E-MTB. Efficiency is not really a concern for me personally . I want to get up a hill fast and 12s is doing a considerably better job, to a point where I find it hard to believe myself. Not much difference in motor heat. Focbox also remains cool, despite the crazy hot summer we have had in Europe. K3glis dual enclosure is efficient/he mentioned he personally runs it at 80a 12s without hitting thermal throttling.

I do have less range now, but I switched from 4x8000 to 4x5000mah.

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I only put premium in my eskate. It prevents BLDC knock and prevents DRV detonation.

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I would suggest you to ride past a road radar with both 10 and 12s. Car odometer usually have quite high error margin(that’s in purpose, bigger tire size than stock can make it even worse) . Depending a bit on the car producers but some can have up to 7~8%. I had 8% on a Nissan car. While driving 100kmh the radar did show 92kmh. It is not given that the bicycle is right either. So I would really suggest you to check that again. What about the batteries where they the samme type, same output? If not then they are not comparable.